I need to setup a system where customers can choose to Request a Quote for a specific holiday package, where they will enter their personal details as well as their holiday requirements (number of rooms, etc.) and will then allow them to view a page which will have a threaded conversation between them and the admin (so the admin can reply to their quote request on the website).

The problem is that most customers won't be registered when they want to request a quote, so I was thinking that the Request a Quote page could silently register the customer as a user (using their personal details) on the same page where it asks for their holiday requirements. The other option I can think of would be to not register them and just email them a unique URL where they can view their quote request and reply to the admin.

Could you point me in the right direction on how to do either of those?