Go to a local panel/paint shop and see if someone wants to do a cash job.
To tell you straight, the TT subarus arent easy to get more power out of. you can make little gains, but the more you play with, the more likey you are going to have problems.
The Lag (or VOD) is a feature of all TT subarus, you can mask it with the like of a Zerosports Sequential control.
Since you have a REV D model, you have the luxury of being able to re-flash your ecu. So make you car breath (CAI/intake piping, Exhaust, maybe a bigger top mount but not really needed) and thats about all you can really do. If you want power, engine swap or buy new car.
You could add things like light weight pulleys and Flywheel.
I would sugguest giving it a birthday with new fuilds (gearbox, diff, brake etc) Drop the sump and clean it out along with oil pick up. Remove mesh filters out turbo supply pipes.
Brake upgrades, Suspension etc is up to you with how much money you want to spend.
Single turbo upgrade parts can cost around $1500 mark, but then you would have to install yourself. Its not for inexperinced people .
there are threads about it around here.