I've got saws with bars up to 32", but the older I get, the less likely I am to pick up a 60cc+ saw anymore - LOL. Sometimes I have to, but now if I can get by with a smaller saw, I do it. I find that a 30-40 cc saw will do almost everything I need to do, anyway.
I use Marine Stabil in my mix year around. Also a cap of Seafoam per gallon of mix. Try to use ethanol free, but it's not always easy to find. Stihl synthetic two-stroke oil. If I know that I'm not going to be using a saw for a while, I pour up the gas and let it idle until it dies. The advice of starting one up every month or two is hard to beat.