ebay is always a good place for old parts... i bought a voodoo 3 pci 16mb last year for an old school gaming rig, but i ended up ditching the idea and nothing came of the rig lol
MAME? Hehe, I suggest you get something a bit more powerful. I know a PII 350 will play most NeoGeo games, but that's about it's limit.
Anyway, unfortunetly, I odn't have anymore cards like that...sorry. I sold my last few just a few months back on ebay. As others said, that's probably the best place to look.