I am sure this has been discussed but want a fresh take. Mapleshade / Timbernation racks?

Corian or other solid surface makes excellent shelving for audio racks because it’s so dense and inert. 

I have a TimberNation Rack.  Very good isolation and very solid, at 135 pounds.  I highly recommend their racks and isolation platforms.

I'd check to see if there are any talented carpenters in your area who could build exactly what you want without any compromises.

All the best,
Nonoise

Sound Anchor is my fav.   

I also like the Salmander Archetype racks - a lot of bang for the buck but they need to be tweaked to get the best sound out of them.

I will add a vote for Timbernation.  The good- great racks, beautiful, solidly built and weigh a ton.  The bad 0 they weigh a ton and need to be shipped from TN.  But they will last forever.