Howdy Dennis,
Nice looking spoon alright! They're addictive aren't they
Maple is generally harder than cherry (depending on the sub species of each) both carve fairly nice though. The cherry will be a bit lighter in the hand and the maple will mostly be a smidge more durable. Both will make spoons that can be used and loved for years.
Generally speaking if you can get green wood to carve you'll enjoy it a whole lot more, at least for the roughing out stages. A lot of spoon carvers basically finish them, let they dru and then take a few super thin shavings off just to make them pretty. This isn't too say carving dry wood is impossible, its just a fair bit more work. Mostly I've used dry wood because I have it in hand, but the green wood addiction is incipient.
As far as tooling, you can definitely do them with just a knife as it looks like you've been doing. For roughing the bowl a gouge and mallet is a bit faster though, even some of the green wood carvers use a gouge and mallet to start. It's mostly a time invested thing so no you don't NEED the extra tooling, you'll likely eventually want it if you do very many. You have to take smaller shavings with the harder wood so it's a fair bit slower.
The big problem for me with spalted wood for spoons is that I like to take mine fairly thin and is hard to know how progressed the spalting is in any given spot as it's basically semi controlled rot. It's pretty frustrating to be 80% don't with a spoon and then you find out there was an advanced pocket right where the bowl meets the handle or right smack in the middle of the bowl there's a big punky spot. If it's really light and pretty I'll chance it, but if you're looking for spoon wood initially I'd recommend sticking with mostly knot free and relatively straight grained (unless the grain follows a curve you want in the spoon then even better) woods to minimize the frustration level and optimize success. Once you've done a bunch and failure doesn't seem quite so costly as you've already gotten past the mechanics is when I'd say branch out to more problematic woods.
Side note on initial shaping, I've been cheating and using a bandsaw because I have one handy, but I've seen folks who were faster than me by a LOT using a small hatchet. Basically the lighter the better for this it seems. So keep your eye open at yard and estate sales for a small hatchet and don't worry about the bandsaw unless you want it for other reasons
. The more acute the blade profile the better for the hatchet so try to avoid the crappy wood splitter wedge shaped ones (they more often have a softer metal/temper as well and you'll want to take this to a razor edge).