First the 60-90- size I really don't like that term at all if you try to fly one of these planes with a 60 it's a real dog if they are ARF's at 8 1/2 lb or more, so lets say 90 size, what you run into for pattern is the same no matter what size 90 or 2 meter is flying time which means more batteries, chargers and balancers, so you would have to figure out what motor, controller and batteries you would need for the 90 size to get the preformance you need, but the problem with EP is that if you buy everything for the 90 size then you will have to stay within that range or then you will have to buy new motors, controller and batteies for the 2 meter, so the end results would be you spend more.
Steve Maxwell