Wordpress Theme Header Edit

We are looking for a modification to be made to our website http://www.iogig.com,

You will see there is a header image in the template that appears on every page containing our logo and Tagline. We like to be able to change this banner on certain pages to a different Image.

This could be a default header like we currently have and then we just specify in the template different images for certain pages, we are used to using editor for making tweaks to the template however this is a little complicated for us.

Thank you