I'd suggest trying to breed some crosses of your own, Light sussex hen to an Indian game cock is ment to give a decent useful sized cock bird and also the females will lay well. Marans are also a good dual purpose bird and will get to a good size if the right strains are used. I've raised Ross Cobbs myself, but I raised them outdoors and on a grain mix rather than the commercial feeds, They were never off their legs, but naturally they eat more and sat down more than my traditional breeds, some nights I had to physical pick them up from the feeders and put them inside the shed , I got them at 5 weeks old and killed at about 12, good tasting meat, good sized bird and good life! So just because the birds are breed for commercial raising dosn't mean smallholder principles can't be applied! Where abouts are you? perhaps you could arrange with someone local to share a delivery and reduce the costs?