The B/RB will require cutting up the engine compartment. If that doesn't bother you, go for it. The package will be VERY tight under the hood.
Turbo power is less about the inches and more about the heads. Go with the combination that has the best heads.

We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind.
- Stu Harmon