Quattro engine's

hello!

I am thinking to bay A4 but I am not familiar with Audi engine.
I think I would like to have a Quattro, but they have 1.8 5v turbo, 2.4 5v, 2.6, 2.8 and 2.8 5v engines
What is the best (fastest) engine?
How big is the different between them(on the road)?

So could someone help me out whit a choice!!!!!

thank you!!

the best engine is the 2.7 twin turbo. however it is only in the s4 (well the a6 2.7t also but that is not much help to us).the engine that comes from the factory with the most hp is the 2.8 30v, found in 98-2001 modles. if speed is the desire thought the best starting place is the 1.8t. it can be easly and inexpensivly moded to have much more power than the 2.8 (which has only a faction of aftermarket avalibility as it's 4 cilinder sibling). a simple ecu chip will get the 1.8's peak hp in line with the 30v v-6.