Types of baritones (not talking brands)

Someday I hope to add to my dulcimer zoo a baritone, because I love those lower tones.  Rather than just order blindly or take the first one crossing my path I would appreciate knowing more.

I gather there are huge variations in size.  Since I'm not all that big myself, it's probably a factor I should consider.  Other than that, I would appreciate knowing the major differences to consider.  Please don't get too arcane, rather keep this a discussion for baritone beginners looking to have a new musical love in their lives.