Affiliate type tracking

I would like to track referrals to a fundraising website via users ID so that the fundraiser participant gets credit for what the visitor purchases on the site. Does anyone know how to achieve this? Also I would like the fundraiser participant to beable to send an HTML email or from the site to prospects (people in his address book if possible) with his userid in the URL that is trackable and a specific suject on this email which contains the fundraisers name. And possibly that purchasers can refer a friend with this User ID intact. Maybe this is impossible. Our shopping cart is created with Actinic if that matters. I thank you in advance.