Hi Sutts,
You'd probably be needing a Neuance C or D platform for this application, depending on the total combined weight of your monoblocs.
Neuance C measures approx 1-7/8" in height,whilst Neuance D is approx 2" tall. Either model constructed to a size of 22" x 19"/20" would be US$195 plus shipping to your address.
Neuance is perfectly suitable with your present Sistrum rack, provided that you have enuf vertical space between tiers to accomodate the height of your amps & platform and that the combined weight of the monos doesn't exceed approx 85-90 pounds.
However,if you're generally satisfied with the Sistrum's character of presentation, I feel that you would be best served by first obtaining a pair of Sistrum or other high quality ampstands as the tweakster suggested.
Altho it isn't an absolute necessity, the optimum *ideal* installation will almost always have each component sited on its own resonance control device.
Then you may later choose to incorporate Neuance platforms into your system, as needed, for additional performance benefits, backed by GreaterRanges' no-quibble satisfaction guarantee policy.
Best,
Ken Lyon
GreaterRanges/Neuance