This DOES sound pretty interesting to try out. However, I'd enjoy a few touch-ups on the 2C02, myself. For example, more than 8 sprites a scanline (how about 16? :P), and either a larger definable palette (instead of just 8 sets of 4, how about 16? :D), and possibly a larger palette, but a hue-wheel-based palette would be fine.
Hehe, if we could use the PCEngine's sound channels, this'd make a pretty neat somewhat-retro-ish system. We just need a cool controller that isn't a piece of garbage plastic like a lot of pc gamepads are. :D