I run a T3/T04E with a .63A/R turbine housing and .76 trim (Stg. 3, T-31) turbine wheel. I get full boost by about 3600rpm. Not really all that laggy, IMO.
In all honesty, man, the specs you posted give us nothing. The compressor housing A/R seems fine, but what are the specs on the wheel? That's the important determining factor in efficiency and such. Find out more info if you can.
Also, I think the best thing you could buy is Edub's turbo. It's a freshly rebuilt (0 miles) T3/T04E. It's a good solid unit, not some aftermarket turd.