Sweet pool man, I should've put my bench under the fall. Last weekend was beastly, I could've used something like this too, there is no shade at all until about 4pm in our yard.
On the subject of PVC, I'd go with Sch 80 as well. Regular white PVC doesn't have UV prohibitors in it, so it will become brittle in the sun after a while.
The unbrella NiN^_^NiN posted is pretty sweet, I may look into one of those at some point.