No offence HayaiCivic, but can't you read? He clearly stated that he's buying a 1998 Jetta GT 2.0- that's an MKIII w/a 2.0L 4.:bandit:
Anyway, Logan- I've ran into the same issue about replacing the stock exhaust, the dealer will charge you up the A$$ as usual so I looked elsewhere. The most expensive part of the cat-back system is the resonator section located just in front of the rear axl. I asked around and found out that you didn't really need it, so I bypased the resonator with a straight pipe to the muffler- it's all legal and sounds just a bit louder (which I prefer). Any muffler shop will help you out- as far as performance goes, I don't have any numbers but I'll assume with less restriction comes more power.
If you want to go all out both Neuspeed and Techtonics makes decent stainless systems.
Cheers,
rpm:toothless