"New to me" 270G Filtration advice

[Druknmonkey]

So i recently acquired a 270 gallon tank from a coworker for cheap (84x24x30). The largest i've ever had was 75 but had been looking to upgrade for awhile. I am upgrading my 75 with my 15" ID to this tank for now. The tank is going to be set up as a SE Asian river tank using a large river manifold and 4 powerheads. 2 @ 175GPH, 1 at 270GPH, and 1 @ 400GPH. I am also using a SunSun 304B canister filter with 525GPH Flow. Along with this tank i received a Amiracle Wet Dry filter and 2 overflow boxes. Only thing it would need is media and the pump. Not sure if this is what i want to use or if a sump would be better. I don't have experience with a wet dry or a sump so this is where i get lost. Pretty sure i need 1 or the other but not sure which is better for my situation. Tank will be gravel/sand mix with a few live plants but nothing too crazy, mostly java fern and crypts. Any suggestions i'd really appreciate it. Unfortunately the wet dry only fits in the stand if loaded from the back so i need to decide this ASAP so i can continue setting up the newish tank. pics included below

New stand

New tank

Wet Dry Filter

Overflows

 

[DDK]

A wet dry that size is going to HAVE to be topped off every 4-5 days or else the pump will run dry. Trust me, and its a pain. Before I had a 75 gallon sump on my 240 I ran one of those 30 gallon sumps and its a pain in the rear. To support sustainable aerobic bacteria you need the bio balls getting dripped on and not submerged or else they will basically drown. I used to just leave it and let the pump run dry just because its such a pain.

Evaporation on a large foot print tank is just stupid even if you try and cover the cracks. Kept it 77 degrees and covered up all the cracks with saran wrap and still evaporate gallons within a week. Mine also wouldnt fit through the doors, I on the other hand had a open top stand so sliding the tank over and putting in the sump was easy enough. I would get a bigger tank, 75gal+ as a sump so you can easily run 1-2 weeks without topping off if needed.

 

[Druknmonkey]

With the way the stand is configured i can't even fit a 75 inside. Gonna look at this more in depth when i get home