How can I add customer info to Receipt email?

The free (in all senses) plugin I have put on offer here:
https://www.whitelamp.com/public/q/A/wordpress-plugins
shows how to go about modifying customer and admin emails.

Off the top of my head, this link:
https://stackoverflow.com/questions/1485668/how-to-set-initial-value-and-auto-increment-in-mysql
will probably help with your second question.

Thank you for your answer. I see your plugin uses get_purchase_log() but purchase_log table does not have customer info. I am wondering if there are functions builtin wpec to read this info, as I cannot find them.
I found WPEC Shop Styling plugin which can show this info but it doesn’t show download links for some reason, so it’s not good for me unfortunately

Obviously the information is there in the database, but whether there are handy functions available already – I’d have to spend some time to find out.