I'd plan for at least 3 pumps:
1/2 - 3/4 hp pump running a canister/cartridge filter (or sand/bead filter).
1/2 - 3/4 hp pump running a second canister/cartridge filter (or sand/bead filter).
Pump to run a pt skimmer (or skimmer/ fluidized bed combination).
Have one of the canister filters dump into a bio tower above the tank, and gravity feed back into it.
Have the second canister filter return with a couple of jets so you can direct flow where you need it.
Pt skimmer would be easier to use if you had a sump... but set it up higher than the tank so it can gravity feed back in.
I'll have a better answer later.