I'm glad you are really into the hobby and have the best intentions for your fish. Hope my advice has been as useful as possible, it is by no means the law (don't do it because I'm badgering you about it, it's just my best advice for you. Realistically they can also live fine in the 50G so take your time in setting the 110G up). What I can guarantee is that moving the fish into a tank suitable for their adult size as soon as possible will ensure that they grow to their full potential and are 100% happy with their living space. It will also be less work for you in the long run. Maintaining a 110G tank with your 2 oscars + pleco will be that much easier than cleaning and caring for them in the 50G. GL with your tank and enjoy