That would be a nice mixed flock except you will likely have to keep the Silkies apart from the main flock or they will likely take a beating from the larger breeds. We had to separate our Silkies from our main flock and keep them in their own separate enclosure for that very reason. Also, I'm not quite sure why you would order both the sex links, and the RIR roo and Barred Rock and Delaware hens. If you are strictly wanting sex links for their incredible egg production, you could just order all sex link pullets from a hatchery and skip the RIR roo and Delaware and Barred Rock hens all together. If you are wanting to breed sex links, you can't breed them from your 1st generation sex links as sex links are hybrids which will not breed true. You can, of course breed your own Black Sex Links by crossing your RIR roo with your Barred Rock pullets, and your own Red Sex Links by crossing your RIR roo with your Delaware pullets. It thinking (based on your statement about using the RIR roo for sex linking) that you are wanting to purchase the sex links to boost your initial egg production; then for the next generation breed your own sex links using your RIR roo and your Barred Rock and Delaward hens. The bottom line is; if you are happy with that combination, then by all means go for it (keeping in mind again the warning about the Silkies smaller size).
Edited by Michael OShay - 10/25/15 at 6:28pm