Got a little more work done last night. I ended up buying two sheets of acrylic and using my old table saw blade to cut. The edges are not perfect but they are passable for sump baffles in my opinion.
I also bought what I thought was everything I needed to plumb in a ball valve off of the return pump, but it turns out that the pump outlet is a 1 inch and all of my other return PVC is three-quarter inch. I plan on coming straight up off the return pump with PVC to a 90° elbow to the ball valve and then to another 90 with an adapter for the vinyl tubing. I could've done PVC all the way up to the bulkhead but I already sealed in the vinyl tubing adapter into the bulkhead. Either way all I need is a 1 inch thread to three-quarter inch thread. Should just be one more piece or so.