I really think you are over thinking things a bit. For the size of tanks you are going to filter, strong large pumps will ne needed along with big media capacity. A trickle filter with a good zoogleal mass will remove most, if not all visable particulates, just by the simple fact that biomass is "sticky". There is no such thing as "no maintenance" in any aquarium regardless of size. When the sizes start getting into the multiple 1,000s, heating and electrical requirements take front row.....and algae..if they are outside. Filtering for claritys sake is a battle best left to diatoms and fine mesh, and yes, time and effort. A large UV and proper biological will make very clear water...way more clear than especially a fish would care about.
I am sure you will find your way. Good luck with the gars and post pics of the tanks when you solve the particle issue.