In the past for sukkos, I've used shop lights with a total of 8 LED tubes, which was probably more light than needed, but now crazy bright. I would run tape/ropes along the full length (~16ft) of as few as 3 beams (or as many as the full 9 beams - depending on the lumens/ft or whatever - to get sufficient light for the space. The whole idea wouldn't be worthwhile unless I can find a way to do it for $200 or less (excluding install, which hopefully I can do myself).
where'd you end up with this? I just put up a new pergola, and grooved a 4' x 1/2" recess into the underside of the joists to put in LED strips 'invisibly". I'd like to set them up in a way that they can be controlled through my smartthings, but that can be as simple as putting them on a smart switch. Don't see any need for RGB in the sukkah. I have a joist every 24", but I plan on throwing in a couple of ceiling fans, so that will eliminate the ability to use 4 of them, to avoid flickering.