Dulcimer-Guitar Style Options?
Instruments- discuss specific features, luthiers, instrument problems & questions
I've been dreaming of an Olympia Walkabout dulcimer for years, but I haven't sprung for one yet. https://olympiadulcimercompany.com/products/
Many "cigar box guitars" have 3 strings and a diatonic fret pattern. The easiest ones to build have no frets at all and you play them with a slide. Anything is possible! http://cigarboxguitars.com/
There are a lot of decent and inexpensive baritone ukuleles on the market now. I got a Kala "Makala" for 80 bucks at Sam Ash and it plays great. Warm tone, nothing like a banjo-ish strumming stick. Four strings, 19-20" VSL. Normally tuned DGBE (like 2/3rds of a guitar) but the strings will take DGAD and (usually) DAAD tunings. Or just remove the G string and tune it DAD. Nylon strings instead of steel, which is a plus ergonomically.
The chromatic fretboard is a dealbreaker for some folks, but creative use of masking tape can mark the frets to ignore (or the frets to use) and sometimes that works well enough. I think it's worth a try, given that diatonic guitar-neck instruments with a rich sound are hard to find, while bari ukes are everywhere.