You can go with just the gasket maybe a light coat of oil to help it stick in place. I use Hylamar (kind of like Permatex) on mine so if I open her up I can re-use the gasket a couple times before changing it out.
As for Coolant I never heard of that brand but it does not mean its good. I use Engine ICE in mine.
So what was broke the lifter shaft or the lifter piece? My bet is the shaft