At M5hosting.com we use Ubersmith. Its designed for hosting and it supports everything on your list. We are very happy with it, and the company is very responsi

At M5hosting.com we use Ubersmith. Its designed for hosting and it supports everything on your list. We are very happy with it, and the company is very responsive to support and to feature requests etc. I have never been entirely happy with a billing system, but Ubersmith is the best for us and we are very happy. Perhaps the worst software I have ever bought ot used was ModernBill (maybe now called Parallels billing). Good luck.