Custom. There is a reason you know the top 3 brands - they are reputable. Aside from the IM leaks a few years ago those are the top 3 because they work.
There are some FijiCube inserts believe that can turn a regular tank into an AIO. Personally, a $10 tube of silicone and a $15 piece of black acrylic and any tank can be an AIO for a fraction of the cost as the big 3.
I love my Red Sea Reefer though. It just works and allows me to focus on not fixing plumbing issues.