Even a 125 is gonna be pushing it imo with a common pleco. it's a 2' + poop factory... w/ 2 Oscars... which are poop factorys.. w/ a pictus.. which is a catfish.. and a poop... you get the idea. and a word to the wary. Your Oscars may get along just fine, or may hit maturity and rip eachother to shreds until you have 1 fish left. So be prepared to seperate if need be, but of course you should hope for the best. And now that I've gone threw some of the negatives. I'de take the common pleco out, and if you really want a pleco there are some other choices that would stay abit smaller, and be alot less bioload. and my experience with common plecos is the bigger they get the nastier they get, they can and will kill other fish in the tank. I'de add a Tire Track eel, and check out the catfish boards for some other possible ideas unless your in love with pictus'.