Is this possible with Magento?

I want to create a private store (disable frontend user registration and guest checkout, only enable the option for the admin to add new users).

I want to give the registered user the possibility to purchase items without paying at the checkout. I don't want to add products with the price set to 0.00, because at the end of the month I want to send them the invoice covering all the purchases for that month (and for that, I want the products to have the price).

It 开发者_如何学编程this possible with Magento?

Please let me know, thanks.

The 'Professional' and 'Enterprise' versions have B2B features to support this.

You can also achieve the same with some free extensions, use Customer Activation with Login only catalog.

For the checkout problem disable all payment methods except "Purchase Order". Orders charged this way can be invoiced and cleared at a later date.

FYI, such features are not available by default in Community Edition.
But this is possible via this Magento Extension called Store Restriction Pro:
http://www.magepsycho.com/store-restriction-pro.html

Hope this helps.
Thanks