Any one know of good open-source software for user login that has features such as a database that shows billing information, tech information, basic user information? And also a trouble ticket area.

Well, the only one i know of that comes close to that is www.PhpCoin.com
It might be lacking a few features but i'm not for sure. It's good though.

check out A Plus Bill. (http://aplusbill.com) it comes close to what you looking.