Thanks Jalat. I'm actually going to go to my mom's boyfriend's house later this afternoon, after I wake up. He's handy when it comes to wood working. Built his own kitchen cabinets. Also makes craft racks and sells them on E-bay. I should have thought of him earlier, just that I've never seen him actually wood-working. We're going to see what we can do with his expertise and tools.

I've revised my drawing. The port is going to be on the outside of the box. It'll be L-shape on the top of the box. It'll let me keep a 5.5 x 5.5 port opening, but not interfere with the mounting of the subwoofer. It'll be different, but should function fine. We're going to round all the corners that the air in the port passes.