Well, just had a quick chat with my mechanic.
Looks like I'll be going with a Garrett T04Z as the HKS 1.00 exhaust housing may still be too small, at this stage it looks like I will be using a 1.15.
The power goal is only 450rwkw/600rwhp. A turbo to make any more than that would be a bit of a dog on the street in terms of power curve.
Shell goes to the paintshop later this week............