So I was planning on drilling the bottom, but I've decided to save real estate and drill the side. I am planning on doing the ECLIPSE L OVERFLOW BOX (1000 GPH). I'm doing the large size so I can set it up as a bean animal overflow. I like the safety and the quiet you get from these setups.
Still trying to decide on the return pump. I'm also considering doing two return pipes so I can reduce the number of fans I need in the tank.
For the ATO pump, my thought is the Neptune ATO kit. I don't have a Neptune brain, but would like to have one by the end of the year. So getting products that can work with that seem ideal and since this can work without the brain, it seems like a good initial investment.