Can't offer direct help, but I do have my suspension-less TT (Planar 3) on a rack on suspended hardwood floor. Tried a variety of things, alone and in combination, under the TT and found that a Neuance shelf worked very well, sonically. I was surprised how well it seems to be dealing with low-frequency floor-borne vibration. So, you may not have to let built-in TT suspension be a big factor in your decision.
Basis or Michell GyroDec
I'm wanting to get back into analog and I'm looking at the the lower-end Basis tables (1400 and 2000) and the Michell GyroDec. (I am open to the Regas, but these others are more appealing to me.) While I haven't auditioned the two brands, I do understand that they have different sounds. Were it not that you have to spend $3K with Basis to get a suspension, I would probably go that way instead of the Michell. Not certain I need a suspension, but I suspect I do with raised floors and a good but not great equipment rack. A high priority in this decision is ease of use and maintenance.Modified Rega arm is likely either way.
Would appreciate anyone's experiences and insights. Thanks. Dan.