Contract/Proposal Integration at Checkout

[IneedHELP3]

Hello,

We are selling a service and require our customers to sign a contract. The process of our sale is as follows:

1. We send a "draft order" to the customer.

2. The customer will click on the link, which brings them to the payment page on our website.

At this point, I'd like to have a contract/proposal that the customer must digitally sign/esign.

Does anyone know how to do this?

I know of the check box apps that forces the customer to accept the Terms and Conditions, but this doesn't work for us. We need them to agree to the contract/proposal.

We are even okay if this is some sort of attachment on the email we send, but this would be a second option.

Thank you!