Sounds like you've got enough space in the coop for EITHER 12-14 cornish cross OR 5-6 regular chickens (either eggers or slow growth broilers need the same amount of space each). If you don't already have chickens and feel like you've done a lot of research and feel confident, I'd recommend getting about 10-12 CX and raising them till they are processed at 2 months old, then taking a month to re-do your coop, and then raising eggers in it. Or you could assess your tractor and consider having the meat birds in it permanently. What methods of predator management are you planning to use? The recommendation is 4 sq ft per CX, but I like to give a bit more (6 sq ft per CX) so there's more litter to absorb the poop and not such a chore to keep it freshened.
What kind of broilers are you thinking of getting? If you get a slow growth broiler, like a 3 month to processing time bird, raising them with eggers could work out okay - they are usually about as active as eggers and can perch and stuff, but are 2-3x the size of the eggers. I would feed everyone 20% protein all-flock feed (chick starter without added calcium) for as long as you have the broilers at least. I feed my eggers 20% year round for their health. Have oystershell and grit available free-choice all the time in separate containers from each other and from their food. For eggers, they need a minimum of 15 sq feet per chicken to be healthy and happy in my experience. For meat birds about the same if you have active ones like the slow growth broilers. The broilers will make more poop than the eggers, so have a plan for managing your litter/ adding more wood chips often. Slow growth broilers will not overeat like cornish cross do, so no need to remove food at night.
If you plan to have them in a chicken tractor, how are you going to transport them into and out of it? Cause herding chickens 2x a day gets old quickly. Most folks keep them in the tractor the whole time, but you'll need to consider predator protection and how secure the tractor and your setup is. For occasional tractoring, transport should be fine.
Now, if you're wanting to raise cornish cross with eggers, I wouldn't do it. They will literally tear each other up to get at the food in the morning, and will climb over and injure smaller chickens. If you had a larger secure covered run, I'd say put chicken wire down the middle, and let the cornish sleep on the (DRY) floor on one end, while your eggers get the coop at the other end. You'd need to turn the litter daily to keep the poop down. CX are sensitive to heat and cold, you don't want them to ever get rained on or have wet feet, because they get sick and chilled easily, and once they're big, if they flip over by trying to step up on something they could suffocate or have a heart attack - they can't flip back over on their own. They'll stop eating once it's fully dark and they can't see, so no need to pull food in that case, but if you have lights outside around their area they'll eat as long as they can see the food. Expect to lose at least 3-5% of your flock to heart attack and leg issues around butchering age. Also research green muscle disease, as CX are prone to this if they get startled once they're big. Nothing beats CX for $/lb of chicken produced, but they require specific management.
