This is a big can of worms. I asked the same question a while ago, and the whole subject of stands/platforms is enshrouded in the greatest audiophile mystique (which says alot). Perhaps it is the 'inner circle' of audiophilia. Also, beware, since I think that there are a number of people that sell what they brag about.
Anyway, Sistrum might be good because of the money-back guarantee. I went with Mana, but admit that I cannot help you decide since I never compared. Come to think of it, Mana also has a money-back guarantee (not sure if for custom build). Mana will build custom racks to your specs (which is what I did), and Teresa at Flat Earth Audio was always very nice. Mana seems to have a religious-like following in some parts. Also, Mana has the upgradability factor as well (it's really quite complicated). Part of my decision to go with Mana was the option to upgrade in the future (potentially with Neuance), and that my system will not be changing for years to come. I have some pictures under 'System'.
Rob