i think you should read a book on turbine superchargers and then start to try to pull together a thread like this. A good book entitled
Turbocharger Theory should be fairly light on the reading butgive you some good understanding of turbochargers. then come back to something like this when you are done. For example. i see a very big problem with a lot of what you are saying. a 50 trim is going to be far to small(read very inefficent) on a 3.3L engine. You will be running somewhere around 45% compresor efficeny at low boost levels(typically you want to be in the 60% and 70%s for streetability na to turbo power) Yes, in general you are on the right track but i dont think you really understand the differences in turbochargers, trim sizes and compressor maps,exhuast housing size, etc. Its imperative to understand how to calculate your engines flow rate, and pressure ratio at desired boost level before choosing what turbocharger will best suite your needs.
how to properly size and develop routing for exhuast on a turbo system is more hit or miss given the variables that you know about your motor and what you are attempting to achieve and how much you want to spend. Calculatiing the best exhuast housing for your setup mathmatically is something that is defiently left to the Engineers with lots of experience due to all the factors that effect the turbine thermodynamically, so most of the best tuners out there will simply use their know how to a point, and within that range try differnt size exhuast housings to get the desired end result.
There really is no "Best", intrinsic value is the important component in engine modification for the enthusiast.
phil