External Aquarium Filters

I am looking into buying the Rena xP3 canister filter for my 55gal freshwater planted tank. It currently has 2 spotted gar, 4 heujeta, 1 pleco, 1 shovelnose catfish. It also has a sand substrate.

What i am wondering is if the filter i choose is a good one, considering i can get it for about 0.

Also it has a spraybar return and i have no experience on how they work. I would like to use 2 Marineland BIO-Wheel PRO 60 bio wheels as the return because i think the spray bar may be to powerful. Is this true and do you know where i could get the bio wheel's. Marineland said they are not sold separatly from the magnum canister filter combo but ithink thats incorrect. The main reason i want the bio wheels is that my fish eat about 200 feeders a week adding a substancial bio load.

I also plan on upgrading tanks soon, this is why i chose the xP3.