I'm hoping to not over-think this one too much. :) So, no configurable "systems" or a solution that works for a large range of conditions or people. It just needs to be for two most of the time, maybe three people once in a blue moon. And, yes, light rain but no storms. I do want the option to use it for shade (as opposed to a greenhouse!) so the polycryo is probably not the right material. I already have the silnylon on hand, anyway.
Fabric width is a little over 60", so if the 5-foot width is sufficient, it makes for a really simple project. I was going to go with 5x8 or 9 unless I was convinced to go larger.