Payment Plugin Where Client Types In The Amount

I am looking for a plugin that does the following:

• Allows a client to type in their invoice number, name, business, and amount they want to pay. (we offer custom solutions)
• Utilizes Paypal.
• Allows customer to choose Paypal or a Credit Card for their transaction.

It would be great if they could sign-up for subscription payments as well, but last I checked Paypal wouldn't handle subscriptions so I was looking at Stripe.

I have a custom script that I could use, but I would prefer a plugin if its available. Currently I am using third party PHP software for invoicing so I really just need a payment system.

Thanks,

Ken