I am using a converted 18th century wardrobe where I have been able to make a lot of simple but positive steps towards controlling vibration and cleaning up the sound, even for a very sensitive turntable. Like Drtalsma says, if you give us the particulars of your design, we might can help.
Taking another angle, the Brits love HiFi and go on about racks. Pick up a copy of the December issue of WhatHiFi and look at the rack section and ratings lists at the back of the magazine. If the vibration situation with your most likely handsome home built rack is unreconcilable, then you can get some ideas from there. Most HiFi boutiques in the States and elsewhere know about and can order offshore products, and some may even stock high quality and decent looking "budget" rack systems.
Taking another angle, the Brits love HiFi and go on about racks. Pick up a copy of the December issue of WhatHiFi and look at the rack section and ratings lists at the back of the magazine. If the vibration situation with your most likely handsome home built rack is unreconcilable, then you can get some ideas from there. Most HiFi boutiques in the States and elsewhere know about and can order offshore products, and some may even stock high quality and decent looking "budget" rack systems.