Spalted maple is best IMO with either a clear or slightly amber tint finish. I think anything else takes away from the spalt detail.

Not dingotone (too big a chance of it not hardening). In addition to the wipe-on finishes mentioned, there are the poly, acrylic and nitro spray options though if you can only work indoors, to stick with a wipe-on. Of the sprays, nitro is the only one that’s easy to get with an amber tint (if that’s what you want), but it’s normally 2-3 times the price of poly or acrylic.