Reliable broodiness at six to eight months of age and easy handling. Won't let other chickens bully them or their babies. Cover large clutches without egg breakage. Sounds like a job for a game hen. I kept large fowl cochins for years, had silkies, lot's of various heritage breeds. Saw nothing I would call "reliable". Had to have an incubator on standby. Silkies hatch OK, them and OEG bantams are about the most dependable thing you can find at all hatcheries and feed stores. I never had much luck with the silkies raising chicks. They just don't have the persona needed to make everything give wide birth to their brood in a mixed flock setting.
I think I will try to get some OEG next for brooding. I had a dapper little gentleman that I re-homed as I wasn't looking to breed banty/game into my line, and the lovely little lady I had, being the curious sort that she was, managed to hop the fence and investigate the wrong end of a rat trap to her demise.
I like Silkies, but I agree that, at least in my experience, they generally lack the ability to fend off aggressive members in a large flock setting...some come close....but most don't. Their odd appearance can make them targets for hazing with those crazy crests by the bigger birds (I have had some otherwise gentle ladies hold and pound a Silkie). Silkies are however excellent "serial brooders." Mine have brooded 3 to 4 times a year, but I did create a separate broody hutch and run for them to protect them and their babies.
My bantam Cochins...granted, this is the only 2 I've ever tried, and they are sisters....are something of mop heads. They keep letting eggs roll out or leave them on the "no zone" fluff fringe to cool off. It's as if with all that extra fluff they are not as aware of where the eggs actually are. They are proving to be extremely broody, so I may see if I can't get them deeper nests to avoid some of this rollage.
Large fowl can be absolutely awesome, but generally, unless you have something like @fisherlady 's Silver Penciled Rocks [drool, drool], large fowl have not been as consistently broody for me. At best, my large girls will nicely brood in spring but not again until next year...if at all. I've had several do an awesome job their first pullet year but then never brood again. A number began a brood but quit early not able to handle the long term. They also don't seem to be as broody prone over their lifetime with the exception of this particular line of Marans I have now...those girls seem to be going broody twice a year, but I am waiting to see how long lived that is. My Marans are fully able to keep the chicks safe in the flock, being "substantial" matrons, but I also now have a good rooster that takes care of chick integration for me. But I know there are those whose Marans never brood. I think it is just this line (she admitted some went broody on her) and the fact that they were hatched under broodies (I've read that can actually improve your chances if the genes are there).
Good thoughts about the OEGB....if the "mop heads" don't improve, I'll trade them out for 1 or 2 nice OEGB ladies as I have heard others sing their praises.
LofMc