All of your tracking needs can be solved at tracking202.com, bevomedia.com or marinsoftware.com. For Tracking202, feel free to use either the Self Hosted Version (Prosper) or the regular version hosted by them (Tracking202). I trust the guys who run that company (known em for a few years now) and I will ensure you they aren’t out to steal your data. I don’t have experience using bevo or marin, but I hear great things about both of them.
Tracking is essential in this business, so always ensure you track every click. You want to know who is searching for what and who is ending up on your landing page, and ultimately who ends up signing up for the offer you are promoting.