Hi Ben,
Sounds like a neat & fun little machine... good to hear that it has a decent gearbox & they have upgraded the brakes too. Is it legally approved with the 3T-GTE?
I reckon you should be able to get that out of your engine with thre right set-up & tuning.
The last "standard" 3T-GTE I dynoed was putting out 135kw at the wheels (or around 195kw at the flywheel). It ran a custom water-to-air intercooler, 3" exhaust & around 13psi boost.
See if you can't knock the price down a bit so you can have a few extra $$ to spend on sorting it out some more.
Post some pics if you can, I'd be interesed to see how it fits & what sort of a job they have done.
Cheers,
3T-GTE.