Trying to work out the correct gearing for the turbo/SC will be a mind fark. First you need to work out turbo CFM, then rpm at which this is produced, and work back from there with internal gearing (yes you're right - centrifugal sc's do gear up inside them. Can see in below pic how the pulley is offset from the centre of the compressor) and then pulley sizes. While always keeping in mind engine rpm, and when you want the response.
To me it seems like trying to re-create the wheel! ;)
If you have family that can make you a decent turbo exhaust manifold cheaply, then I think you'd be silly not to just go with a conventional turbo set up. :)
Have a look at what I have been doing for the last 8 months to answer the carby vs EFI question! :dance: ~Yes they are a bit harder to get your head around (I like carbs for how user freindly they are), but half the reason why I'm going EFI is to expand my own knowledge as well as upgrade my car!!
150hp (110kw) isn't too unrealistic, but that would be starting to push 15psi, so be careful on turbo selection. :hmm:
Should be able to quickly find all of the figures you need to work out the CR on this site.
My appologies for car make/model......... :P