chaoscreature

Your best bet will be finding someone who has them installed and try it out. Even if it's not a 993 if you have been in a car with solid mounts and one with stock mounts you will get an idea of what you are in for. I love it, but I think I am in the minority.
turbokraft makes a nice semi-solid transmission mount. WEVO's are IMO the best value for engine mounts.

levtron

I went with Wevo Blue for the engine mounts. They are fantastic. I would recommend them for street or track.