400 Build vs 440 Build

I'm leaning towards doing the 400 stroker just to save the room. I have what I've been told is one of the best b motor intakes in the Holley Street Dominator and I have a 800 holley dp for on top. I'll probably throw a 1" or 2" spacer in there if it'll fit under the hood. The only thing I'm hung up on is selecting the cam package and rockers. Any input on this?