First i want to say: Yes i have serached the forum, yes i have read all the bad things about phpmanager.

I only need a automatic account set-up, and i think phpmanager is best on that.
What do you think?

Does phpmanager and whmautopilot send an e-mail with the usrename and password and adress and stuff right after a customer have ordered?

phpmanager nono

If you want to have a good steady billing / support system, throw your hopes on better softwares like modernbill..but since you are only comparing whmautopilor and phpmanager, so be it. WHMautopilot will prove to be much better then.