Your title says homemade, but from your post it sounds like you're looking for stuff that's already out there...
Anyways, I'd recommend
Descent. Might seem a bit pricey, but you do get a lot in that huge box.
Descent is basically D&D as a boardgame. One player controls all the monsters, and each other player has their own hero. Heroes level up, acquire equipment, etc. It's not cooperative, though; it's the "overlord" (I think that's what he's called... been a while) vs. the PCs.
There's also a few expansions, including one called Road to Legend which introduces ongoing campaign rules.
I'm sure someone else here can give you a better description. Personally, I don't care for it, but I think it would serve your purposes well.
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