Ad design for London Underground board

Hi there,

I am interested in designing an ad to go on the London Underground. The ad will revolve around medical tourism for laser eye surgery. The size of the poster needs to be 12 x 8 feet long. I have attached a document with further detail. I would be providing all pictures and text to be used and it will be a straightforward and simple design. I would appreciate if you could let me know how much it would cost end-to-end and provide with any samples of previous related work.

Thank you,
Kostas