Painting the back turned our to be a huge PITA. Used rustoleum flat black latex paint and it basically created a layer of paint on top of the glass. When it dried it came right off the glass in one huge sheet. Went back and used my standby of black plastidip and was done in a few coats.
Next plumbing. I might try out flex pvc for the return. Never used it before and then regular pvc for the drains.
That’s a sharp stand and is in line with what I want for my 40B. Do you have a rough guess how much it cost you to put together? I have seen other threads with costs but always for much bigger tanks.
Stand is probably about 550-600 including the light stand part. I like that in the future I can change some parts around and use it for bigger/smaller sizes. They are not cheap but they are bulletproof. Goes together with an Allen key.