WHMCS Email Verification

We have a WHMCS solution. In our solution we want a hook or code to do three processes before finalizing the order We are using the "Comparison" order form but it would be great to have multi form solution 1) After the client fill the first step with the email we need to send out an email to verify the ownership of that email. The client should receive a message (on our web) to visit his/her email and verify that. After clicking the link they should be able to resume the checkout process. 2) We want to use a coupon validation technique to verify whether a coupon was assigned to a specific group of emails in a particular domain. Such as [login to view URL] ... If the criterion is not satisfied the client should be advised to use the email with such domain. 3) If a client from a particular domain wants to sign up we want to automatically be able to provide a specific pricing for them (special discount) Good English skills is a MUST! You should be able to communicate with us via Skype, GTalk, or Phone.