Affiliates Bulding Campaign

I want to start an Affiliates-Signup campaign for my ecommerce website in herbal products. I need affiliate from good PR websites and marketers, for which i am offering 20% commission from direct sales and 5% sales in Tier 2 sales.. life time commissions. Please provide me details of how you would like to run this campaign and what will be the cost/milestones. My preference is to pay you on commission basis (as an affiliate), but i can also consider per signup fee. Thanks.