My understanding @ejb123 and @Josef.koney disagree, they think you don't need PVC etc, unless I misunderstood
I'm not totally understanding this, I use a pvc.
The pvc is just to allow the tarp to role. If you want to go outside and do it urself, go ahead...
As for the slant, there def needs a slant and having some kind of ledge/track for the tarp to be on is a good idea. The 2 ways to make the slant is either have the succa boards made on a slant (little more difficult, but no wind problems, no support problems etc.) Or to have your succa boards straight and just have a track that's on a slant.
I hope I'm being clear...