That is a great idea. I think an office would be more of an asset than bunkbeds or an outside kitchen anyway, especially for a couple. I know some people like to eat outdoors, but cooking inside and then eating outside would still be an option. Personally, our dinette is used more as an office than it is an eating area. I shoot video all day and then do a lot of file organization and downloading as well as editing, blogging and updating email as well as camera charging. Having a dedicated area for this would be a very valuable space.
It still sounds like a lot of work and I would certainly be interested in seeing your progress. Please keep us updated