I also had a oddly shaped stand (almost square) and I had to custom make a sump. What I did was designing the sump myself, drawing everything on a piece of paper, taking it to Tap Plastic and had all the pannels cut there, and take the parts home and glue everything together myself. Cutting is the most demanding part of the process which I do not want to do myself, and Tap Plastic charge by square footage only. The acrylic cost me about $100 (not as cheap as $25), but I saved at least $200 that they will charge if they glue it for me. And more importantly, it fits my stand just the way I like it.