I too am planning on buying a VW and I chose to go with the Jetta personally because the Passat is a bit too expensive for me (and a bit too large) and I hate station wagons/hatch back's...they just don't look cool to me, so that ruled out the Golf. Their just not my style personally.
Your style my be different than mine, however, but if I were you, I would go to cardomain.com and look at what people have done to their Jetta's. The most common year for those seems to be 1995 and 1996. I'm going with the 1996 when I buy. If you take a look and read some review's on the vehicle, you will find out that there are a ton of things you can do to/with that car. Just look at what others have done to it; the possibilities with that car are endless, or so it seems.
Going deeper into the Jetta class, you see that the three main classes of the vehicle are the GL, GLS, and the GLX, respectively. The GL is the most common one I see and is the most standard. It started at around $14,000 in 1996. The GLS is the next step of that gives you many more options on the vehicle, including power windows. The last is the GLX which is the GLS with more power...I think it's a 1.9 turbo diesel, but I really don't know. Beware though; at around 70,000 miles tons of things go wrong with the electronics, this is why I personally and going to go with the GL because everything the GLS has seems to go out, and since it's European, it costs an arm and a leg to repair since the warranty is almost certainly up. Also, leather is very uncommon in these cars, but is available. Many are manual's too. The size of the engine is a 2.0L 4Cyl. 8 valve.
I have learned more throughout my research of this vehicle, but I don't have the time to talk about everything I've learned about this car. But mind you, I don't even own a VW and haven't ever...but I plan to. So I don't have any actual experience with them, so I suggest you read reviews and go test drive them!
As for where to buy, look at carsoup.com and eBay, those are the only ones I can really recommend and know of. As for pricing the vehicle, I suggest kbb.com before you buy. However, kbb.com assumes the vehicle is in very good condition, which is not always the case (duh!).
lol Sorry for the length!
Have fun with it man,
Yea, though I walk through the valley of the shadow of death, I will fear no evil: for thou art with me; thy rod and thy staff they comfort me.