181925 e-newsletter/listserv program

I am completing work on my website, [login to view URL], and my programmers built in a basic listserv program to allow users to maintain mailing lists and send basic newsletters. I would like to upgrade this section of the site to something similar to constantcontact.com. basically, we are talking about creating numerous e-newsletter templates, a full mailing list suite to maintain email addresses with personal information, full statistics for sent emails, and everything else that contast contact does. This would need to be built into my existing site, using the structure of my site, and whatever database information that needs to be migrated over. If you want to use joomla or any other pre-built system that has all of the features of constantcontact, that is fine. there is no reason to build from scratch if it already exists. work on this project will begin around the end of the year, and should be completed within 30 days of starting. programmer must speak english.