Pegasus, I feel I need to warn you, if you ever get a hint of hair algae that miracle mud is going to make it absolutely impossible to get rid of. That stuff feeds macros like nothing else on the market, it kind of makes no sense to use it since the whole reason for macros is to absorb the phosphate, nitrates and whatever else out of the water, and make it pristine...by using miracle mud you feed the macros instead of have it absorb it out of your system. It's a lot like running a chiller and heater at the same time, they cancel each other out. Miracle mud is loaded with phosphate and nitrates to feed plants...it's a fertilizer.
As for in the same "box" you have different chambers. A sump with a refugium is all in the same "box' but each section is a chamber. I have never found a single person who thinks UVs are of any use, it does kill your tiny critters, not all of them...but why intentionally kill any of them? Going through the skimmer or return doesn't hurt them, they do get pushed to the display to become yummy treats for the fish. The UV, much like the miracle mud, is a waste to have, and actually bad for your tank. It won't crash it, it's just not really useful.