THOUGHTS ON GUITAR SIZES
The player is the music, not the instrument.
Tonally, any guitar body size works perfectly for any music style or genre.
Only if you are playing live acoustically, with no amplification with loud instruments (banjo, violin, bagpipes etc), does guitar size become a concern.
Typically, the larger the body, the more projection, bass, and general volume it has (but, pickups…).
Having said that, my smallest parlor is loud, but if you play, say, in a traditional bluegrass band without amplification, you may need a larger sized guitar.
Fingerstyle guitar need not be limited to an OM: Bert Jansch, John Renbourn, and Michael Hedges played a Dreadnought, & Duck Baker a classical.
Bluegrass does not only emanate from dreadnought guitars: Normal Blake’s 00 12 fret.
Jazz need not be played on an archtop guitar: Julian Lage plays a Telecaster.
Country isn’t only played on Telecasters: Maybelle Carter used an L-5, & Dave Rawlings an Epiphone Olympic, & Chris Stapleton a Jazzmaster.
Blues can be played on not just 1920’s to 1930’s small bodied guitar sizes.
Be yourself, like all the musical giants were.
(Wanting to emulate the sound of original recordings is a separate issue.)
I recommend finding a body size/shape that suits your stature. If you have shoulder issues, a smaller body is best.
If you’re mostly only playing cowboy chords on the first half of the fretboard, I recommend considering a 12 fret to the body guitar.
Again, Any guitar body size works perfectly, tonally speaking, for any music style or genre.