I have an Orpington girl with legs like tree trunks. I noticed them the day I brought them home, freshly hatched. So don't let that worry you. One way to tell if your RIR is going to turn out to be a cockerel is the tail feathers. They grow beautiful green tail feathers.
Yes "Orpington girl with legs like tree trunks" is what I always say.
My gals are HUGE!
If you want a very docile breed, Orps are great and their eggs are big. My roos never went through a bad hormonal stage at 1 year. (A little too frequent mating the hens & a little comb pecking of each other around their 1st birthday.) They never even entertained the idea of chasing one of the children or circling them. I only had to get rid of one adult male orp. He wasn't aggressive all the time, but unpredictable. Too many good roos around, so that boy went to freezer camp. He never actually attacked a person, but kept trying to stand his ground & attacked plenty of shovels, brooms, & the pooper scooper.
However, orps are not very efficient with the feed. They also take a long time to mature. I'm very impressed with my Dominique hen. She's intelligent, a great forager, has natural hawk camouflage, gentle, and very, very friendly. I've heard most Dom roos are fairly gentle, but I never had one. That may be a breed to look into if you want a good dual purpose heritage breed.
There is just the two of us, so we will definitely have a surplus of eggs. Our parents will reap those benefits as well, especially since I enlisted my father and father-in-law-to-be for a lot of manual labor getting the coop built. If only you could pay for everything with eggs! What we have left between our family and friends who want them we will likely sell by just putting a sign out at the end of our driveway. In about 100 years that coop will pay for itself!! lol 
