Search Google for "FSI vs TSI" and you'll get tons of threads about it. TSI is better all the way around; better PCV system, better fuel system, timing chain instead of timing belt, no cam follower issue, less oil consumption than FSI, the list goes on.. Also with the TSI you don't need to upgrade your HPFP if you go stage 2+. Go TSI if you can but I wouldn't completely rule out FSI if thats all you can find. Just make sure it was properly maintained and try to find one that's been stock its whole life.
I have an '07 FSI that I bought earlier this year and it was completely stock its whole life and maintained by VW. I had a few issues with oil consumption in the beginning but I fixed that by replacing the valve cover and now I barely consume any oil at all. I don't have any cam follower issues either and doubt I ever will if I keep checking it every 5000 miles as a precaution(since I'm stage 2, if car is stock you don't need to check it that often). Also if you do get an FSI and your cam shaft, follower, and HPFP get destroyed, its still covered under an extended 10year, 120k warranty. Just call Volkswagen, give them the VIN, and they will mail you the extended warrenty information. Many people have had this happen and they took their cars to VW and they replace everything at no charge.