I had a very similar spec to Antti several years ago with over 250bhp as well. It was a standard bottom end with a standard gearbox and it has been fine for nearly a decade now. In any case, power don't put the rod bolts to test, RPM will. Also gearboxes will be destroyed by clutch use, grip, and neglect.

It's funny how the tables have turned. Usually it's the finnish who have defined the UK-bhp as ~1kw

To the original question:
The things you will definately need are a proper intercooler, management and something slightly bigger than the original turbo. It doesn't really matter if it's cvh or zvh. Everything else will just help make the power with less boost/heat.