RE: Vibration reduction mounts
I've seen those vibration reduction mounts, and the price tag.
A couple of schools of thought here 1. I know lots of people with several hundred flights on an airframe with "stock" hard engine mounts. that suggests it's not required.
2. If I was really worried about the engine vibration I think I'd try to get some washers with the rubber insert around the hole. I believe they're used for sheet metal or fiberglass roofs. The rubber sticks up enough to provide a cushion between the enigine mount and the firewall.
Now I haven't tried this, it was just a thought on my part
I think it just might work.