look around a little more and you should be able to find a very nice S4 for under 20grand.. a friend of mine found one for 15k!!!.. granted with lots of miles, but since he's part owner in renn-art, he obviously doesn't care... however, for the budget you have, you should be able to find even a newer one...

but i highly recommend k04's later on, of course!

or the upcoming garrett turbo options from ATP! [:-]