well just to give you a couple of ideas, you could up rate the turbo to a td04 or td05. these are coversion that uses the turbo of subaru impreza, i have seen these kits selling on ebay for around £300 td05 (is more expensive). Maybe worth looking into for the power you want. You will need to do a couple of modification to get maximum power out such as uprate fuel delivery (injectors,fcd) and air flow (front mount intercooler and induction kit) these are just a few to give you an idea, these modifications are not cheap to do, but if its a car your going to be hanging onto then i think its well worth it hope this helps.