I was planning on running 2,but probably won't be purchasing them at the same time,so the HOB's will be running with 1 until I have the $$ for 2.Thanks for all the suggestions.If you are planing on only one filter (Really, two should be used on a 120 IMO) as much as I LOVE Eheim I think the FX5 would be best out of those choices.
Those marineland cans look nice but do they last for years and years? Nobody knows because they haven't been out that long.
If by chance you are going with two filters, 2x2217 would be fine.
Thanks for the tip on Kens,I don't think I would have thought to look there,also check www.kensfish.com for prices on canister filters, his have been the best prices that I have found. On my 120g oscar tank i have a c-360, an AC110, and an Emperor 400 (i think). I plan on ditchign the emperor and adding another c-360 when i save up the cash. 2 c-360's would be great on a 120g.