So does the stock computer know how to run two higher flowing injectors say 61 65 etc vs the 55 if you change heads. Also are 4 barrol tbi worth the price?

First question, No.

Second, If I were looking to make more than 500hp w/TBI, a 4bbl unit would seem necessary, but more important is the need for more than just two injectors.

I don't think it's likely that you need, or will benefit any from a 4bbl TBI.

True so is TPI the better way to go or just buy some vortecs and run a computer or carb style vortec.

I want to make atleast 250hp and right now I do not have to work for couple months.

I would consider a 46mm, modded TBI for your needs.

http://www.rvmorsemachine.com/index.html

This is one of the best investments you could make.

http://www.dynamicefi.com/EBL_Flash.php