hey! 8-bit sounds aren't bad, they're awesome!
if you need real shitty synth sounds, grab some old casio used for like $20. what could be better(worse) than the real thing?
i mean, think it this way: who wants to sample an instrument that truly sounds shitty for the sake of it sounding shitty? that's like giving free slaps on the face, there's always that one person who may want them but that doesn't mean it's really worth the time as nobody else does.