Just saw this on SaltwaterAquarium.com that Planet Aquarium is selling prebuilt setups similar to Red Sea, Waterbox etc.....
To me this is an absolute gamechanger. They even offer custom alterations on the website. Not sure of the price but the standard setups are priced competitively with Trigger sumps!
https://www.saltwateraquarium.com/aquariums/planet/?sort=pricedesc