Hello Tref.
I have posted a bit about dual purpose and table birds on my web site.That should give you a few ideas.
But as a taster..
The cockerel brings egg numbers into the gene mix when mated, so if you use an Indian Game cock unless you have a strain that has been bred to lay more than normal for Indians your breeding pullets that do not lay many eggs. This depends if your going to eat the pullets
.
Oddly enough it's the female side that carries size of body,which connects with a game bird, as they carry heavier amounts of meat on the breast.
I used an Australorp cock, as they have Croad Langshan in the makeup and Croad have Asil in them. (Both Game breeds). Your looking for a cross that 'nicks' or dovetails into the other birds gene pool to create a bird that is going in the direction you want it to go. Once you start messing on breeding new strains it takes over your life.Its a fascinating hobby.