If you go the custom route, then you can get a camshaft that doesn't have as much lift, so it won't interfere with piston/valve clearance, or retainer/seal clearance, etc.
You don't need a .580-.600" lift camshaft for factory heads anyway. In addition, a lot of the Comp Cams off-the-shelf roller cams are pretty noisy. If you don't mind, it's one thing, but some guys really mind if their engines sound like sewing machines.
If you're looking for a hydraulic roller, I would do something like a 276/276, 220/220, 110/104, .501"/.501". That would be keeping an eye on overlap so that you have sufficient vacuum for brakes, etc. Keep in mind that if you go roller, the cam companies usually tell you that you need their lifters, valve springs, etc., but you will also need a steel distributor gear and different pushrods.