Yes the 98 is indeed a good one.� I assume is is the 2.8 and not the turbo since it is still around after almost 20 years.� The 12 valve is indeed a robust engine and there is a site dedicated to this:� www.12valve.org 

This is quite simple and easy to work on but you will have to remove the front bumper assembly to work on the front of the engine (H20 pump, timing belt....).� Not so with the same vintage A6 but then you are stuck with an auto.

It will be one of you favorite cars ever!!!

-Paul