Delawares are supposed to be great dual purpose birds, lay well, and provide a decent table bird as well. they were once the preferred meat breed, before Cornish X's were developed. You'd probably do better with birds from a breeder rather than hatchery birds, they tend to be not very true to type, leaning much more toward layer breeds than true dual purpose. When I say breeder, I mean somebody who has been conserving the breed, keeping to breed standards, not somebody who got off-type hatchery birds and bred them.
They tend to be non-broody. If you had a standing flock of Delawares, you could keep a few hens of some other breed for brood hens. They don't care who laid the eggs they hatch. My best brooders have been dark Cornish, light Brahma, and Australorp. I've had Orpingtons, and they didn't brood much at all, but other folks have had some that would brood all the time.
Bantams (I had mixed breed bantams, I don't know which pure breeds would be best) are often great little brooders, too, and easy to tell which eggs are theirs, so you don't set the wrong ones by accident. Since they're smaller and lighter, they're less apt to break eggs in the nest.
When I want eggs from a particular hen or group of hens, I isolate them in a separate pen for a few days until I get as many eggs as I want to hatch. Sometimes I let them out with the others to run around, after I collect the eggs for the day, then take them off the roosts at night and put them back in the iso pen, if I have time to mess with them. That way they don't get totally deprived of foraging. (I let mine free-range)
Edited by me, to remove what annoyed the Op. That wasn't my intention.
Anyway, good luck with your chickens, I hope it all works out well for you!