Either the AC 110 or the Emperor 400's will work just fine. I personally like AC 110 more but either one has gotten great reviews and you can't go wrong. Its just a matter of personal opinion. Also, my buddy used to have a Magnum 350 on his 75 that did okay but I don't believe it could handle the bio-load of an adult oscar and pleco. I just was not impressed with the flow at all.