Hi ben if you read my signiture that will be good for around 240bhp which is the most you can really squeeze from these engines unless you are ready to spend some big bucks and go ko4 turbo or bigger! Theres many good mappers for these engines and they include revo, apr, shark, r tech and obviously custom! I run a revo map as like to play with the settings through the sps software i have got! Exhaust is always a good one with a sports cat or decat if you have freindly mot man, miltek, blueflame are good but i got mine made custom as didnt like how expensive they were and runs real well! Panel filter in the original airbox is what most go for but i opted for the bsr optiflow kit with a heat shield and have had no problems! If your going to go this far then you could go for a stage 2 map which means it would be good to buy a turbo inlet pipe which ypu can get from forge motorsport but there are other makes out there that are also considered good quality! Also will need some injectors from a s3/tt225 which are plug a play, this will allow to get the fueling correct for your new map! You can also opt for a front mount intercooler for your car but i choose against it as most inexpensive kits require a cut out of the crash bar which i was not for! If i find a real decent kit which fits underneath it then i will be purchasing! Hope that helps a little with the start of your modifications! If youmdo choose however to go bigger turbo just do it staright away and dont go down this route i have described first as you will be buying same parts in different fitments and will not be cost effective!