I've created a great automated solution to create VPS accounts automatically via any billing solution specifically for Virtuozzo. When a customer signs up via the ordering wizard, the system will create the account for them just like if it were a shared hosting account. I did it originally for myself, however, from what I understand, most of the billing solutions out there only have a solution for Hyper-VM and not Virtuozza. I am not sure of the interest, but I think there should be quite a few others that might need something like this.

Please email me for more info steve (at) md5 dot com