I used a "bearing" style button that I got from my cam manufacturer but found I had too much "end" play. I had two options, weld a plate to the inside of the timing cover or dimple the timing cover where the bearing would contact the cover. Using my hydraulic press I made a 1 1/2 inch dimple in the plate about .050. I had thought of leaving the gaskets out and going with just silicon to bring the timing cover closer to the bearing on the end of the cam. There is an aluminum cover you can buy for this purpose but it's hellish expensive. To fine tune the clearance, I drilled and tapped a 3/8 hole in the back of my water pump housing making sure it was in line with the underlying cam bearing. With the pump removed, and using an Allen wrench I can turn the set screw in or out to exert slight pressure against the metal timing gear cover. Thus I could "fine tune" the cam float to exact specifications. It's been that way for two years now without issue. I like buttons on the face of the cam but I fear the plastic and metal style will cause metal particles and possibly wear through the timing cover.
