An octo tank requires the same water quality as that of a good reef tank...so most of us use protein skimmers...I would splurge on the skimmer, get the best one you can $$ !
On the bright side (pardon the pun, I couldn't resist) you don't need to have halide lights, so just a standard flo. fixture is ok...
Be sure an put your tank in the database when you get it up and running...good luck!
greg