Solid lifter on hydraulic cam?
It is possible that your valve springs are dieing on you. Since you have adjustable rockers you can check to see if it's your valve springs or it's your lifters that are the problem. Adjust you valves to zero lash and go make a run, if your valve floating is still there it is your valve springs if it goes away then you were right and it is your lifters. I would do this before you spend any money on the cam & hardware, it would suck to put all of that new stuff in the motor and find out you still need valve springs.