Hi,
Thank's for the quick answer.
Btw, they are only 4 or five well-known and registerd customers. They don't want to provide on-line payment information, but they'll pay "directly" once a week.
So, following your indications, I'll build a simple Joomla+Virtuemart to see if it's convenient for these requirements.
Again,
Thank you very much,
Newbie01