Affiliate Website Design and SEO

I am looking to build an affiliate marketing website. I am looking at purchasing a suite of 47 websites from [login to view URL] I would be installing them on a root domain that I own with each niche site installed on a keyword relevent sub domain. I am looking for somone to design a page search engine friendly page for the root domain and to link to all the sub domains. I am also looking for SEO to drive traffic to all the pages including article writing and submission and social bookmarking and am willing to consider a monthly charge for this. Please suggest what you believe to be the best method of setting up this site and driving organic traffic and the expected traffic that you can drive to the site.