350kw is a shit load of power. Especially if u are a newbie to performance cars. I have a 33 making 277rwkw with bilsteins, 255 G3's and strut braces, and still wont grab till 3rd (if ur lucky) I can tell u what i have done and what i have found out since i have done it. First u will definately need a front mount so u can up the boost safely. With out turbo upgrade u cant run over 13-14 pound though. So next i would do fuel pump and reg. Next i would get rid of that air filter ( the last thing u want is a bit of foam 2 go through your turbo) and go for a K&N style. U can then highflow the turbo and up the boost a bit more. The injectors at this stage should be fine as apparently the standard injectors are good for round 400hp. I went for a top mount GT35/40 which will require a new manifold, new turbo lines, ect, more expensive than highflow but sets u up for more horsepower. I installed a set of tomei cams (optional) but assists with turbo lag and if u go the top mount with larger turbo u will need external gate. And ofcourse re tune ur power FC. All this set me back 12k and the motor blew. At this point fitted 550cc injectors to safeguard further detination. Is now only running 12pound but im guising that will be close to the hp limit befor u will need to rebuild. Forged pistons and rods, new crank, RB30 bottom end, flow the head, decompress, and see how much boost you can run before breaking. im guessing the rebuild will be close to 6k, but until gear box and diff give up, will prob get u close to that 350rwkw. Problem is power FC uses air flow meter so u will never pull high kw with a computer upgrade. My advise about boost controller is go cheap. up the boost and save the money, sell the Power FC and buy Motec wich doesnt use an air flow meter and has its own boost controller, so to spend $800 on and AVCR would be a waste. However i have one that worked well before the turbo upgrade. To do it properly i would have to agree u will be looking at around $20,000, so maybe start mild with intercooler boost and fuel upgrade and see how u go?