Website Designer / programmer for complicated project

I am looking to design and launch a new website services which will need a database behind it along with security for many users. I am looking at some prices to instigate the devlopment of the project. However I am protective of my idea and would need a confidentiality agreement. Although I would like a face to face meeting with the individual I select to work with I am not too worried where they live as long as it is in the UK.