I need to build a website that pretty much is a near clone of this one here 

http://www.mytempnumber.com  
To see inside beyond the signup use the user name Bewham and the password Rocco1

This company will be sending me their API. I would also need the site to be able to charge via Paypal Web Payments Standard so that API needs to get applied as well

I need to know what you need from me. I thought maybe powerpoint slides showing how I wanted the site to look - 1 per page. It also needs to be to a certain extent changeable by me.

What else might I need to provide you to quote me?