The block will mate up to your tranny & heads. you will need to run your intake manifold.
Are you planning to keep it turbo'd, or are you just wanting to use the block?
There's some talk in the engine forum on www.bbs.legacycentral.org
about swapping heads over from the RS's. It will lower the compression ratio, however they will flow better.
So depending on what you're doing or what you want.....will depend on what is "best"