The coil pack problem is only an issue on the B6 1.8T cars, 2002-2005. The 2.0T does not have any issues to my knowledge of blowing them any more than any other car.
I used to have a B7 2006 A4 2.0T Quattro 6 speed. I had GIAC chip for 15k miles and loved it. Great car, a lot of fun all year round.
I miss that car almost every day. I only had one problem in the first 24k miles, a coolant flange broke, covered under warranty with an A4 loaner.
As Jones said, CPO gets you 6/100k warranty, and 05 and 06s had free maint for the first 50k miles. Also, they were the last for transferable CPO warranty if I am not mistaken.
The 2.0T is an amazing engine. As Jones said, a chipped 2.0T is putting out K04 1.8T power, and add a turbo back exhaust and you are putting out fully supported K04 1.8T numbers.
They are putting out around 300wtq and 215-230whp.
You could also look at some CPO S4's, their values have been plumiting do to the gas prices and general economy. I have found some CPO 2005 S4's with about 40k miles on them for around 25k!!!!
Good luck, and hopefully we will see a new Audi post soon.