For the most part I cannot tell the difference when they are small. How old are the ones you will be selecting from? Watch them for a little bit before you pick them out... some of the toms will start puffing their feathers and doing a little "strut" and they start doing that pretty young, I wanna say around a week or two in age.
I always keep the largest tom from my flock for Thanksgiving, and then I keep some of the smaller hens in the freezer for meals when it is just me and my husband. I would guess that even though the toms are larger, they probably eat more as well.
Ooops, and I misspoke about the roosts. They do like to roost, I just don't have one set up for them, and they seem to be okay with it. Last year, after I slaughtered the pigs, I moved the turkeys into the pig pen/barn so they would have more room, and I did notice that several of them would roost on the fence at night.
