Realistic T4 build. Is it possible?

[rustbucket]

Okay, so I want a T4 for my project. I'd love to have one of Jake's, but it's not really an option. I'd like to spend around 2k max. So here's what I'm thinking:

Used T4 1.8L from German Auto Dismantlers or such
Dual 40's or 44's, whichever best suit the engine
911 cooling (while saving for a DTM)
Pretty much stock internals

I've read where the stock 1.8 has 70-80 HP (don't remember exactly). I'm good with that. I'm not building a street killer, just a sweet driver. I want to do 85 on the interstate, but I'm not going to be street racing ricers. I want the potential to go bigger later, but want good stuff while I'm waiting.

Okay, so what I want to know is (and please don't flame me if it's been asked before somewhere):

1. Is there a drastic difference other than price in the 1.8's and 2.0's. I know there is a slight HP increase, but other than that?

2. What would be the drawbacks to starting with a 1.8 from a bus? Are just the heads different, or would I lay out a ton of cash on other parts in the conversion? In other words, is it best to start with the Porsche engine or does it matter?

3. If I can find one of these engines locally, what should I want with it? Just the longblock? Intake too? Exhaust?

4. What are the limits of the 1.8? Max HP numbers I could squeeze without swapping jugs etc... (or with just bolt ons)

5. Finally, what kind of performance can I expect out of the stock tranny? I've read on other forums that when you get more from the engine power wise, the tranny performs just fine for street use. True? Should I look at a Freeway flyer?

Once again, I know most of these are newbie FAQ's, but most of the threads I've read are concerned with major HP or just the 2.0. That's not my goal. So if you wouldn't mind, I'd appreciate it.

BTW- If you guys need some one to build a FAQ's I'd be happy.