The only true bolt on turbos are stockers and simple hi-flows like GCG.
Having said that once you start modifying cars the first rule I have learnt is nothing in the performance world is truly bolt on. They always need trimming, new studs or exotic nuts that aren't available at 2pm on a saturday.
The way around this is to spend more money on Japanese product like the HKS range. I bought my second HKS turbo from here at SAU but was missing a few oddball sized nuts etc. It took lots of running around at the last minute to find something suitable. Mitsubishi had them but wanted $18/nut!!
I spent 30 minutes fitting my bolt-on catalytic converter last Thursday to find that the last guy had modified the existing front cat flange to fit the exhaust rather than the other way around. The new cat is perfect but a fat lot of good that has done me. Another welcome to the modified car scene for me. I fitted a Fenix radiator (thru SAU NSW) it fitted almost perfectly on the R33 barring the AC temp sensor. The stagea will not be so easy when I get around to removing that pissy little OEM radiator.
Turbos have nothing to do with beauty contests they are there to pump air and this one, even running at 90% of the posted dynos, will be great to drive.
Check out the 200rwkw at 4000rpm.
I think once this is bolted up it will be a nice bit of kit.