You need to remove the last colon from your link.
I don't really know about the ounce rating. I normally get a small sample and feel it. The ripstop nylon structural sheet from my bridge bag was of a weight that must have been something in the region of 1/3 oz per square foot. It seemed to withstand my weight well and I could kneel on it without any feeling that I was going to go through and felt thicker than my HH Hyperlight Asym.
As for the material, I don't know what polycarbonate coated polyester would feel like. You had better order a sample. I imagine it would work well as a tarp, at least.