I learned to play finger style on a nylon strung Yamaha electro-acoustic model. The nut was pretty wide, not as much as a full blown classical guitar but considerably wider than your average steel strung acoustc.
Songs that I can play comfortably on my Yamaha, I struggle with on my Walden acoustic steel string as the spacing is too close together for my old fat fingers when plucking away.
The classic Seagull cedar to S6 seems to be the obvious choice to solve this problem at it has possibly the widest nut at 1.8" that I've seen. Short of having a custom instrument built, I wonder what other acoustic guitars have nuts this wide or bigger?
I'd even thought of converting a 12 to a 6 string by removing every other string as on my own model it is really comfortable to play finger style.
The only thing that puts me off the Seagull is that it's not a solid wood construction.
(pronounced: equal-sequel) "I suffered for my art.. now it's your turn"
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I will not tolerate anything less than 44mm - not even in the otherwise lovely 1980s Tiawanese Yamaha dreadnought I could have bought for a song earlier this year but passed on because the nut was 43mm.
Seagull make all-solid guitars,, including this one in spruce and mahogany with a 45.7mm nut
* https://seagullguitars.com/product/maritime-sws-natural-ae/
Most European-made guitars have a 46mm nut as at least an option and very often standard. You can have any Lakewood you like with a 46mm nut - and Lakewood make really lovely instruments, quite reasonably priced for what they are, and screaming bargains if you can find one second-hand.
* https://www.lakewood-guitars.com/guitars.php
Dowina guitars are very reasonably priced and mostly come as standard with a 45mm nut, or they will hand-make one to your requirements for far less than you'd spend on, say, a Gibson or a Martin.
* https://www.dowina.com/
12-strings almost always have a 48mm or 50mm nut which is a bit much for most people. I tried my nice Cole Clark 12-string as a 6-string for a while (after I decided that fingerstyle 12-string was not a sound I liked) but despite starting on a 50mm classical and playing 12s (Eko and Yamaha) for most of my life, 50mm was just a little bit too much for me in the end, Well, 50mm plus a shallow D profile I never quite got used to without pain in my not-so-young-anymore hands. 48mm I probably could have managed, and 48mm is quite common in 12s Just don't buy a 50mm 12 and expect to be happy playing it as a 6-string - my experience suggests that you'll struggle.
E10 and E20 00 and P10 and P20 parlours. Bear in mind these are all small bodied 12 fret guitars and significantly more expensive than the Seagull.
Anyway, I have played all types of guitar apart from electrics throughout my life (now 67). I would prioritise tone, ease of playing and love for a particular instrument over any individual instrument characteristic which would just cause me to dismiss that instrument out of hand. I think I might have missed out on some good instruments if I had said, "Oooh, can't look at that, the nut width is too narrow".
Also (!), nut width is not the only factor in finding a neck 'nice' or not.
I'm certain my 'go to' instrument is not my first choice solely on the grounds of nut width. It's just an all round comfortable instrument with a great tone and suits my playing.
Thinking about it a bit more, playing my smallest instrument, I might have occasional poor note definition with a slightly greater incidence of difficulty holding down certain notes in certain positions in certain pieces. With subsequent dulling or buzziness of notes. But that wouldn't stop me playing it 'cos it sounds lovely. :-)
I am very sensitive to nut width, only mildly sensitive to string spacing at the bridge, and really don't much care at all about the neck carve. (OK, very wide, ultra-shallow necks make my 60-something-year-old hand ache, but I don't dislike them, only have physical trouble with them.) But within reason, any neck carve is fine. I barely even notice.
Now think about the next player, say one who cares a lot about string spacing at the bridge. (There are plenty of these.)
The next player again is fussy about neck carves, and so on. We are all different and look for different things.
The problem with converting a 12 string is that they are engineered to handle the tension of, well, 12 strings, so probably would be quite stiff and unresponsive with 6.
Just because you're very picky about one thing doesn't necessarily mean you'll be equally picky about another. As you said, everyone seems to be different.
Then I had two cars fail their MOTs the following week, which has set me back somewhat, but the plan is to buy a Furch when funds allow. Anyway, I think a Furch Blue with 48mm nut would be killer.
It really does depend on what you learned on and what you are used to far more than it does on the size of your hands.
If you started on (say) a Strat copy with a 42.5mm nut (common enough), 48mm feels huge and, depending on how long you played the narrow-not things for, you may never get used to it. Same story with those Japanese acoustics with tiny necks (Takamine, I'm looking at you.)
If (like me) you started on a classical (50mm) and spent most of your life playing 12-strings (50mm and 48mm nuts) or bass (only 4 strings but set well apart) you'll find getting used to standard 44mm nuts very difficult. I'm still not really used to it despite owning half a dozen 44mm instruments these last four years, and playing them every day. I just collected my new baritone. It has a 46mm nut (nominal, it's probably more like 47mm in reality) and it is sooooo nice after the 44mm squeezy things. Oddly enough, I'l a little put off by the wider RH string spacing but only a little and I dare say that will pass.
Now look at someone playing a mandolin. Mandolin necks are bloody near microscopic! Tiny even for people with very, very small hands. But people get the hang of them (buggered if I know how) and play them well even with hands the size of soup plates.
Anyway: main point, the size of your hands isn't the issue. It's how your brain is wired.
Second point, I don't think barre chords will cause you any problems. You are more likely to discover issues playing intricate open-position fingerstyle stuff. ("Intricate" in this context meaning "tricky by your standards", however high or low those standards are.) Further up the neck (say 7th fret, just to name one) all necks are wider and nut width doesn't make much difference.
Short answer: you'll be fine so far as the barre chords go, but watch out for the other stuff.