Here is what little I have to offer:

For a .60 size 4 Star you won't need any vibration damping so keep it simple.
One piece or two piece both work fine if installed correctly. The 4-stroke mounts are a little longer because some of the engines have the air intake behind the head.
I'm sure you will be using a glass filled epoxy style which drills and taps nicely.
The only problem I've had lately is a one peice mount where I had to cut away some of the webbing between the rails at the back to get my OS 4-stroke to fit in.