with that hp you want shay, I think you would have to do some internals within the engine. Remember S/C is always on and never stops until engine is off, which means alot less km's per tank. T/C are easier to install and prob have more power at the end of the day. I think you need to do some further research into which S/C will fit for your engine, I dont think alot of ppl do S/C's for opels.

Good idea though, however how long do you intend to keep this car for? think of the money you need to invest for it and in like 5 years, how much will it be worth?