How can I enable wholesale customers to pay by account?

[nmittels]

Hello, 

I'm looking for a way to have wholesale customers pay by account. Currently we use wholesale club to manage wholesale pricing, and while they have a net terms payment option. I'm not sure it is really what I'm looking for, as we have 

• Allow customers with certain tags to pay by account. We could have 10 customers tagged to "Group A" for example, and they would all have the same account.
• Set limits per customer tag, so customer group A has total limit of $30,000 and if their total open orders hit that threshold, they cannot order via account. 
• Message at checkout informing customer they have hit their account limit
• Ideally, a back-end interface showing the status of the outstanding orders per customer group.
• Allow team to mark account as paid up to certain dollar amount.
• Hide payment option if customer is not in an active customer account group.

Any suggestions on the best module to handle this, or do we need something more customized?