visitor counter

I humbly beg help from the scripting gurus that inhabit these halls.

I need a modified visitor counter. I would like one that notes the date as well as the time when an avatar visits. Also, unlike my current counter, if the avatar comes back some time later, I want that recorded as well. I would also like it to email me the list only if there is a change in the visitor list. Similar to the list I have now I would also like it to be resettable. If anybody can supply me with a script that meets these requirements I will gladly pay what you think is fair for your work.