I thought frame tanks were supported by the frame. The bottom glass being recessed. My old 150 was like that, sat on the old school wrought iron frame at edges only.
As to styro under frameless, I don't have specifics about differences between the 1/2 or 1" white and 3/4 pink but the frameless I have was shipped with the custom stand and a thin piece of homosote, perhaps 1/8 or 3/16 tops.