below are my comments ...
This works very well for me with the current DB structure.
But how do you handle the case that one customer buyes webspace package A and after a month he buyes webspace package B on top?
I think we need a more general approach where we have recurring and non recirring billing items of several types. And I wont mix up the billing system with the domain robot. And why should customers not be able to order secondary dns services? Thats a common feature.
I agee with you, till. I won't mix up both systems. Although i think a db-table domain is desperatly needed! It's also a security feature! At the moment i can use notgood.customer-a.org where customer-a.org belongs to someone else on the same server. With the domain-table u can assign domains to your customers - and they can only use assigned domains for dns, mail and webspace. Furthermore you can add a flag for domains not registered over the isp (Sec.-DNS only).
ok. XML export can be one option beside pdf.
I will take a look at their implementation. But most likely it will not fit for waht we need.