I got an turbonetics 60-1, with a 0,58 rear T4 housing. It will fit your setup perfectly. Mileage on the blower is 6,200km (2 oil changes), it was a customer's that he upgraded for a PT67 about 3 weeks ago. Turbo is in perfect condition polished with the elbow welded for a Supra setup, like you have. I dynoed the customer's car on this 60-1 setup, at 1,45 bars @ 523 rwhp. It has full boost at 2900 rpm and it starts boosting from 1500rpm. Pretty nice turbo, and i think it's exactly what you are looking for. If your's is in absolute perfect shape like this i can go ahead and exchange it. Please PM, because i'm located in Greece.
Cheers
Dimitri