BALTIC BIRCH !!
Definitely the best.
Zero voids, impeccable finish. lightweight, machines easily. Looks great with a clear coat.
Tons of information out there if you google baltic birch.... a few build threads on this website too using baltic birch...
heres the first thing that came up under google for me.
Wood Finishing Tips for Woodworkers
www.woodworkerssource.com
PS, baltic birch machines, router or saw, beautifully. and once cut to shape it only needs a clear coat or two.
Ot has zero voids, there is nothing to fill, no voids to trap moisture. Cut it to shape, glue the parts together, finish... DONE.
Add up the cost of every other option and baltic birch is a best buy.