Printable Poster Design

I need a poster designing that can be printed by my customer to display in their chosen environment.
The poster should be saved in A3 and A4 format to allow for printing on various printers they may have.
It will contain a mixture of eye-catching images and engaging text which I will provide.
It will also contain a table/box to allow people to add names to it so a group of people can get together and take advantage of a single visit and cost benefits accordingly.
All material will follow after we have established best way forward.