if you're stock and like a smooth vibration-free vehicle, don't do solid mounts regardless what they're composed of.
as far as the clunk, i have all brand new mounts and i dont have so much of a clunk, but more of a slight click when i shift out of park. i assume it's normal. every GP ive been in does it. so who knows.
Even solid metal mounts aren't as bad as people make them out to be. I put them in my Stealth in 07 and daily drove it with them til I parked in at the end of February putting about 45k miles on them.
2011 Mitsubishi Lancer GTS - DD mode
1991 Mitsubishi 3000GT - Many mods to come