The "road most traveled" and thus the safest/easiest will be the PICT 30/32 with an SVDA distributor (Single Vacuum Dual Advance). This will sacrifice power over 3600 rpm, but is simple, durable and easy to tune.
Sadly, the vast majority of aftermarket performance parts need a great deal of modifications to make them function properly.
If you are the sort of person with a knack for mechanical things, and have the time and tools to devise and perform the modifications, then substantial power increases can be achieved.
But if you are not well-versed in the idiosyncrasies of performance VWs then keep it near-stock and you will have far fewer frustrations.
And of PARAMOUNT IMPORTANCE is to keep the intake manifold heating system complete and functional!!
I recommend you consult John at aircooled.net for performance parts and guidance. He has excellent parts and advice.