Jeff,
My condolences go out to you man...... You are doing one of THE most stand up things I've ever heard of. I have nothing but respect for you.
If you have ANY questions whatsoever we are all here to help. I have a decent sized indoor pond myself (around 1K gallons) with rays in it. Mine is made from landscaping brick since I rent my house, I have to be able to move it, and with all the flakey friends I have I can really only count on myself, so I can move my entire pond with only the help of me, myself, and I. I built my own filter from a rubbermaid ag tub. IF you need any advice whatsoever just say so.... I'd be glad to walk you through how I built mine.... There are a few things I'd change but for the most part I am VERY happy with it, and it was able to keep my pond clean with 13 rays in it..... If pics would help just say the word.
Good luck man...... I applaud you.