I have the exact size tank you do with a reef octopus skimmer. I have the dual skimmer HOB
. I paid 150 for it online. It's a monster skimmer. It's two skimmers in one. Bad stuff: it's ugly. The two large pumps go in the tank. Also it took about 3 weeks to break in and I always had to adjust my collection cups and the directions SUCK! But after the break in period it was an animal. Pulls out the nastiest stuff you can imagine. Also pretty quiet for a large powerful skimmer. I guess if you want it to work for your water quality and not worry about aesthetics it's great. I just hid mine behind a mountain of live rock. Love it.