Really, Neil?  What exactly is dissapointing about raising your own meat from non-perfect stock?  The resulting carcass may not win any prizes but it will still cook up just fine and nourish the family.  Don't you have a puppy to go kick or something?  
I haven't gotten to the harvest part, but the last batch of 'surprise' pullets contained some white rocks that are growing at a nice rate.  They are intended for egg-laying homes, so I won't have any carcass data on them.
For my meat endeavor, I have selected a 'surprise' batch as well.  This way I can see myself how the different breeds grow.  
I understand the desire for hatchery chicks, some of us don't live in the country where y'all have chicken farmers out the wazoo.  We are dependant on these hatcheries to supply us with reasonably priced chicks.  (For those who argue that heritage breeders will ship eggs, I spent a FORTUNE on breeder eggs and ended up with NOTHING!  There's no guarantee so I was SOL.)  
So for my $0.02, I'd suggest one of 2 paths.  One is to order a "heavy surplus special" from the hatchery of your choice and learn by raising them which breeds YOU like.  Or, if you really want to pick one breed, just for the sake of having one breed, I'd suggest the white rocks.  They are pretty, mine are growing well, and all data here suggests they dress out nicely.