The gt20 will make that power under considerably less stress and at far higher efficiency than the standard turbo. The restriction at that point is exhaust mani and injectors, so it doesn't really matter how big the turbo is. Sure you could put a gt22 or 25 on and get a 1800bar frps and new manifolds and you might just about push it up to 210, but is it worth it for 30bhp and a fraction of the reliability.
Tbqh I think you won't necessarily need anything more. You'll be making torque figures similar to an e90 m3 in a car that is half a ton lighter, and it's the torque you'll feel up to legal road speeds. Have a look for a 30-70 videos on stage 2 306 hi, you'll get an idea.
For what it's worth I'd suggest looking at slightly bigger/different turbos too. The gt2052 is from landys designed to have boost at low revs, ie probably not so great higher up the revs.
Tbqh I think you won't necessarily need anything more. You'll be making torque figures similar to an e90 m3 in a car that is half a ton lighter, and it's the torque you'll feel up to legal road speeds. Have a look for a 30-70 videos on stage 2 306 hi, you'll get an idea.
For what it's worth I'd suggest looking at slightly bigger/different turbos too. The gt2052 is from landys designed to have boost at low revs, ie probably not so great higher up the revs.