CDI without rev limmiter?
 

what's a good replacement CDI unit that won't rev limit me to 8000rpm? My bike wants to go past this in top gear

Anything not cheap
Plenty options in china including CDI and cool in 1

Is it a CG or CB? If it's a CG, just get a bigger front/smaller rear sprocket. The CGs, IIRC, make peak power around 7k anyway, so it won't get you that much more.