What's your opinion on those roller cam 318s, with 302 heads, as opposed to the earlier 318s? I've got one I'd like to do the same high revving build you're doing. I think they all need help breathing, to start.
If you want to go roller cam, then the roller block is the way to go. I'm not a "big" fan of the 302 heads for any kind of performance. 302's seem to work fine in next to stock applications.