I like the XE 256 but depending on springs and valve weight you might want something a little less agressive. I would run a little bigger lobe on the exhaust myself. The smaller camshafts that you mention are not much bigger than stock camshafts. You need to watch material they are made of as well because we have cam gear wear problems with some of them. We use a billet core like a solid roller so that we can run a steel gear. The core is more and thus the cam cost a little more but I feel safer with it. They run about 329.00 in most cases.
As with any flat tappet camshaft make sure you break it in with the right
oil so that you do not lose a lobe.
Good luck, Keith