Depending on your outside temperatures. We have couturnix in an outdoor coop, so i don't see why you couldn't use a tractor. Buttons I'm not sure about they are pretty delicate.
Most domestic quail have lost the broody instinct. We have tried to let ours go broody and hatch their own without any luck.
I would be really carefull about that, I had 4 buttons in a pen and all got eaten buy 6 foot long rat snakes. Those guys can scale the hardest of walls and fit through the tightest of spaces. They are big and scary and I swear we made that pen bullet proof and he still got in. Best to put them inside.
I have my coturnix in a large rabbit hutch, in with two hen button quails outdoors. they have an indoor part to keep out of the elements and a tarp to keep out the drafts.
I plan to build the coturnix a tractor next spring/summer to let a few out to enjoy the grass and scratch (like they enjoy doing) in a few small pairs at a time fo ra few hours a day.
I will be separating the coturnix quail into trio breeding pens (they are just hanging wire pens) next spring/summer. <---these are simliar to Sportees picture above. The button quails will stay in the rabbit hutch.
I dont use nest boxes at all, as i dont think mine would use them, they lay whereever they want to.