Off the top of my head I would say welsh harlequins, buffs, and silver appleyards. Don't have any personal experience with any of those breeds so I can't help you much with how well them perform.
X3 our SA aren't even full grown yet and are HUGE! Great foragers, easy to put up at night. Looking forward to egg laying from them. We have 2 exta drakes about to be processed with the roosters this next weekend.
P.S.
Hubby just added French white Scovy for meat birds as well.
I second Anconas, ours lay about 260-280 XL-Jumbo eggs/yr. The drakes dressed out at about 3-4lbs, but we are working on increasing that. The flavor of the meat was absolutely divine!
I would say that appleyard are best I never never ate one but I have raised muscovy for meat and put my appleyards in with them and they grew fast. I know that my appleyards lay a lot too.