Ability for customers to be able to pay for multiple invoices at once by credit card integration

Hi there!

I would be great for customers to have the ability, either through Stripe or PayPal integration, to pay for multiple invoices at once by credit card. 

Also, if they could see all outstanding invoices for their customer account & maybe even their credit limit as per set on Cin7, and select which invoices they want to pay for now that would be even better.