Development of Professional Website

Kindly send proposals for the below: The requirement at a high level is to create an end to end? website for Speaker Bureau with admin features to manage the website along with e-commerce payment system as in [login to view URL] (the speaker generates an invoice incase of any additional costs because of delays etc). If the speaker does not generate an invoice within 48hrs of the event, then an automatic invoice is generated and sent to the requestor. The website should allow payment through multiple gateways (paypal,etc) The website should contain a calendar management system, so that speakers can look up their open time and agree to requests from requestor. This system should enable speakers to block their time (even for events outside of the website - similar to functionality in societyofindustryleaders.com. The key reference sites for development would be (i) [login to view URL] (ii)? <[login to view URL]> The website needs to be very professional (creators of dating sites or other small business sites, please refrain from bidding)