I do not see why a program like MPA or others might do the job, the principal would be nearly the same.
However on the broad explaination... If its a company that delivers physical products with order fullfillment then a shopping cart system module might be the answer your looking for, but at the same time keep in mind alot of the technology Adult Internet has developed one can be sure that the proven biz models are tough enough to handle anything "Mainstream".
Kinda a broad question so ya get the broad answer
Hit me up on ICQ if ya got any questions
ICQ: 78943384