I'll be renewing my flock of Welp Hatchery's Slow White Broilers... THE best all around breed ive ever found. They won't suit the OP, because they only come in straight run, but for people who want birds that lay early (the earliest of any breed Ive had... they started 10 days earlier than a mixed pen that included some Brown Leghorns!) and well... lay right through our bitter winter's, PLUS are efficient meat birds that breed true... you can't beat this breed.
They dress out at 5# about 2-3 weeks later than Cornish X hybrids, but thats several weeks earlier than any of the "heavy" laying breeds. They arent nearly as compact as the CornishX birds, and produce significantly less breast meat, but produce a carcass very similar to the "old fashioned" breeds, but much, much earlier.
We still prefer the Cornish X for meat birds, and raise a few hundred every year on pasture, but I always want to keep at keast half dozen Slow Whites on hand (with a couple roosters) in case TSHTF , because efficient growth under those circumstances will be vital.
I do like my Americaunas and Whitings True Blues, PLUS some Cuckoo Marans (my second choice breed for TSHTF preps), just because i enjoy a colorful egg basket. And the Americaunas and True Blues are very lightweight birds, which are admittedly more efficient to feed for egg production alone. But old laying hens are barely worth butchering even for soup, they're so scrawny!
Summerthyme