[Wild83C10]

Best bang for the buck would be a Master Power T76 for a stock type 350, but would suck on a 454. In order to properly size the turbo you need your horsepower goals then calculate how much air you need and look at a compressor map.
Putting a custom turbo kit together isn't all that easy, but if you do your research it wont be that hard. I have been assembling all of my parts for about 8 months now and I am almost finished with mine. I have watched for deals and bought new stuff from other forums (new parts that guys have sitting around because they changed their mind). I still have about $2500+ into my setup, that includes a $400 S475 and I am doing all the work myself.
Don't forget to upgrade your fuel system.

I think you should read Maximum Boost by Corky Bell before you go buying a turbo. Not to insult you or anything but your knowledge of turbos sounds very very limited.