I ended up buying them. They should be perfect for my application (assuming they don't leak).
The collector surface is totally flat, imagine a bunch of square tubes next to each other except its all one piece. the backside has fiberglass sheeting for insulation which is good because these will be propped up on a flat roof. they will also be much easier to mount than standard plastic panels. I have 8 4x10 for a 13,000 gallon pool