Wood for the back and sides. It has to be long enough for the increased length of the body. The sides have to a little longer as well. The pics below can be enlarged by clicking…
First, I’ve had this set for a few years. Tamarind, with spalting. It’s interesting and engaging. It’s not lightweight though, and I think that was something mentioned as important.
The next wood to consider is Spanish Cypress. This is probably the wood that your nylon string guitar was made with. It is sort of yellowish/wheat colored, without much grain feature. It would be a good choice for a baritone. I have many sets of this wood, so here are just a couple of samples.
Next is another blonde wood, Movingui. Lively and interesting grain and figure. Here are two different grain figures.
More options: Below left: Palo Escrito. Right: Birdseye maple
There are more options. We could explore the Brazilian Rosewood options. There is an necessary upcharge, and the options are limited.