50cc pro saw with a properly tuned chain will do a fine job for you.
As said by
@Jay Hansen, no need for a bigger saw for a couple trees.
This coming from a guy who would typically use a ported 70cc saw for that..
My BIL has cut wood for many yrs with his old ms290 and a 20"x.325 chain and has cut a lot of wood that size and he's still running it, a modern 50cc saw will be lighter and have more power.
Another thought is a 60cc saw and a reduced weight bar, then only fill it half way. People laugh about filling them half way, but if your wanting a lighter saw, you probably won't mind the weight savings or stopping a bit sooner to take a break to refuel/oil.