Looking at what you have to work with, I would toy with taking the big buff girls and putting them under the red/gold and what looks like blue male with feather leggs a couple shots down the page. Work on getting as much size, pea comb, yellow leg color, and foot feathering, and type as you can get out of that line before worrying about adding feather colors much. Once you have established a fairly consistent "Brahma-ish" look, you could put a light Sussex male over some of your gold hens to bring in silver columbian color, and then breed back for type. I would concentrate on building the bird, the colors you can play with as opportunities arise.