Considering upgrade and going sumpless

[Aquattro]

Curious why you don't want a sump? For the cost of an old 75g or something, it hides all the stuff. You don't need large overflow boxes, you could have a single pipe.
A sump does give you more options for skimmers, heaters, reactors, etc.

All that being said, the sump really only hides gear. If you can arrange all your equipment off the back and sides, then there's no real difference.