I currently own a first gen Camaro with a 427 BBC/4 speed combo.  I'd like to build a new car for street use and had a couple questions.

First, it looks like I need a new engine, transmission and rear end to get deep into the 11's with any reliability.  After pricing out some cars, I was wondering if buying a 6 cylinder car would be a cheaper way in considering I'd be replacing the entire drivetrain on a SS or Z28 anyway.  Questions:
1) Are brakes identical
2) Do I need a new computer or engine wiring harness?
3) Do I need a new K-member?

Clean 6 cylinder cars are a lot cheaper now and I am not sure how many replacement parts would be needed.  The other option is a high mile LS1 but most of these are pretty beat up and I'm looking to avoid any body or interior work.  Any suggestions would be most appreciated.