[1] The max valve lift has nothing to do with valves contacting pistons. Duration & overlap is what affects P to V clearance.
[2] There is nothing wrong with Comp Cams cams per se. They sell more cams than anybody else, so more failures. The problem is todays junk flat tappet lifters; there are only 1-3 companies making them & they supply ALL the cam companies. If you do not want a cam failure, get some NOS 25+ yr old lifters......or have an old stock set of lifters re-faced.
[3] You have a good parts combo for what you want to do. Could it be better? Maybe, but you already have everything.
[4] Look at using beehive v/springs. These require less spring tension to control the valve train & your cam/lifters/valve train will last longer.
[5] I would use the Isky 280 Mega Hyd cam with Comp #26986 b/hive springs