I ordered the "All Heavies" special assortment from McMurray, 25 heavy breed roos that I raised for meat. Several different breeds of their choice, RIR, White Leghorns, Delawares, Barred Rocks, etc. They matured slower than those hybrids, but also ate & pooped much less than what you're describing. I also like it that I don't have to butcher them all at once, been doing 2-6 a week, since about 17 weeks old.
I raised them in a tractor because I didn't want them getting too tough by running around, and I didn't want them getting into fights with the Lords of the Layer Pens. I would order this assortment again and especially so after reading about the mess & feed bills the hybrids cause.
We've also been butchering the occasional mixed-breed roos that result from a broody hen's hatching. They also do not require special care or extra food. Right now we have an enormous young cockerel we call Moby Chick. I'm looking forward to inviting him to dinner in a few months...