Best Isolation HRS? SRA? Zoethecus? Symposium?

I would strongly suggest Grand Prix Audio.

I use brass Mi-Rollers, right up there with the best on the market.... http://www.enjoythemusic.com/magazine/equipment/1004/mirollers.htm

Check the Finite Elemente Pagode Masster Reference.
Great engeneering and build quality.
Probably my next buy.

To answer your question clearly: yes, an isolation device will make a big difference. Black Diamond Racing Cones give good bang for the buck. Symposium roller ball feet work a bit better, especially when you have the tungsten carbide balls, but they cost a lot more. (You pay the price for hard balls.) I haven't tried most of what the other guys are having.

I use a non-audiophile rack, too. Depending on the configuration of your shelves, Ken Lyon at Greater Ranges can custom build Neuance shelves to fit your rack. I use one for my digital source, and Ken custom made it to fit my Salamander cabinet.

I also use Symposium Rollerblocks and Aurios. Aurios are used in laboratories to isolate sensitive measuring/testing equipment. So, as far as passing the real world test, Aurios have the pedigree.

Frankly, I don't know that I can hear a difference using this stuff, but I figure they can't hurt.