8-bit/nintendo/c64/chip sounds

I realize the irony of spending a grand on Logic to make music that most people would hammer out on a 10 year old Gameboy with Nanoloop but I'm looking for AU plug ins that make that flavor of sound.

I've found a few promising ones but I'm looking for an AU plugin like the Tweakbench ones for PCs that specifically emulate the NES or GB sound chip.

Also, has anyone tried vst wrappers? Any recommendations?

-Bob

PBG4 1.33 Mac OS X (10.4.4)