I would build a big skimmers or smaller skimmers in series for each system..
will you have liverock in the system? like 300-400lb's worth?
I would match the flow rate though the sumps with the flowrate of the skimmer(s)
and get non preasure rated pumps for closed loops.. (cheaper per GPH
Have you considered plumbing all the tanks together? larger pumps are generaly more effecent in design and you could use just one pump for the return from the sump area.. and one big non preasure rated pump for a big closed loop..
this system volume really isnt all that big.. the total flow could be as low as 3,000 GPH
Im not too confedent that the canisters are much good for anything but chemical filtration in marine setups.. and they are alot more maintance IMHO
accumulation not a consern? some of the critters you named off seemed to be NO3
intollerant.. if thats the case you wont want to add sponges/bio-balls/filterfloss and the like unless its getting removed and replaced/cleaned often and without live rock your kinda stuck with extream amounts of flow and hard wet skimming to try and remove all debris before it breaks down into nitrogen or PO4