(I am not a fan of tapatalk, sorry to say for all the other users out there... but its great for getting photos posted!)
Anyway, I have a local Custom Concrete Shop that sold me some "bones" from cancelled/substandard work... they cut apart poured countertops for Kitchen and Bathroom for me at a killer price! The concrete is pretty inert: it does not ring when 'knocked.' Granite is good for this too. So is a good wood cutting board!
Anyways... drilled out and set threaded inserts into the slabs using epoxy. If using wood cutting boards, just drill and screw in... maybe a little glue on the threads as you do. I used outriggers with spikes, but it is just as functional to put the spikes straight into the platform. Level it. Put your sub on top.
The feet on my sub were two-part... there was a small rubber cone that was easier to remove that the posts, so I left the posts and put the Soundpath Feet on the stock posts.
SVS claims that your sub will perform better, as well as eliminating the energy transference vibrations. This has been my experience. Especially when I used the 2-step approach.
Regarding what you can use as a platform, check out the wood cutting boards on Webstaurant.com, if you choose to go this path. I'm sure it would be cool to use a big Boos board for this, but its at least twice the cost. Just for comparison, the concrete shop was highly competetive with the wood cutting boards... only reason I did that. Plus they look cool AF!