I was wondering if any of you have enough experience with a trouble ticket reporting software or "helpdesk" software to give recommendations ...

Specifically my interest is in a software that fully integrates with (more-than-one preferably) email so that email responses in both directions are added to the ticket itself. I've read that some programs only allow a customer to open a ticket by email -- but do not allow two way addition to the ticket once the ticket is created.

I need the ability to upload images to the ticket and maintain them.

I want a purchased solution - not a leased service.

perldesk.com is the most often suggested.

I have read a little about helpspot but don't know anyone using it http://www.userscape.com/products/helpspot/
(it seems to have many features I need)

Serio only integrates into one email box: http://www.seriosoft.com/service_desk_software.htm

And ultimately - this would be within a secured system where the client has logged in already; if possible, I woulk like to pass user variables (log in name etc) to the software when the client wants to make a new ticket.

Any comments or suggestions?
Thanks

We use Kayako and it does everything your asking and can be purchased.