Eric Group
Masterpiece
Water Elm is another that is great for Bonsai!I would say perhaps THE single most under utilized tree for Bonsai is readily available in a wide range of American Climates: the Winged Elm!
Get super twiggy, great leaf reduction, almost impossible to kill, grows in any type of soil, propagation is beyond easy- like INVASIVE SPECIES easy!- if you don't like the wings you can pick them off most the branches without substantial damage and frequent pruning/ bonsai training slows the growth to where you won't get many/ any wings frequently.... Personally I like the wings sometimes thou,must adds an extra level of interest when produce consistently, almost like a cork bark Elm!
Bald Cypress too though they are much more widely used now than in the even recent past...