Since completing my intercooler upgrade, (something I'd recommend to anyone)I'm looking for a computer as well.
Link make a full plug in unit. Have seen dyno sheets of factory turbo cars running 150kw at the rear wheels with an exhaust and the link.
The microtech MT-8 has been used on some I've seen also. The new High Performance Imports mag has an article on an mr2 with this computer. Reasonably accurate article too.
I think others on the list have an MT8, maybe they can give an opinion on that computer.
Any aftermarket computer is only as good as it's tuner.