Thanks for all the comments. I will hopefully be getting a tank that comes with the filter, lights etc all included with the tank, so fingers crossed that the filtration will be suffice for that particular size tank?
I have one Oscar, two Pleco's, two Angel's and One Blue Acara. It would be nice one day to have them all together but obviously Oscar is going to get too big. All my fish are babies at the moment so I'm doing some planning now (and money saving ) so that by the time they all get too big I will have my new tank and everyone can be rehomed accordingly.