Script(s) needed

[Sapience____]

I want to set up some affiliate links on some pages.

I want to do some pay-per-click links.

I need some scripts that will log, time link(s) was clicked, date(s) which link(s)
if the link(s) where used to buy something as so I can then redirect them to a receipt on another site as to record sales so as to get my percentage from the pay-per-click link(s).

I want to make sure that the companies don't make out sales have not come from my site?

Any idea's, links to or suggestions please? (Thanks in advance!).