John,
The biggest challenge I faced with adding pull out shelving to my Tour Master under the sink was finding a combination of manufactured drawer units that was close to filling up the available space without wasting too much of the cabinet volume. Clearing the drain plumbing was a further challenge...
You have to balance depth, opening width, working height and of course have a strong enough structure to actually mount the mechanism.
Look at Rev-a-Shelf and start with the 5225 series that can fit a 9 inch opening and are under 35 inches tall working height -- here is a link to their web site:
http://www.rev-a-shelf.com/Common/Produ ... 5%20Series
You did not mention what the cabinet depth is for your coach's pantry, and that may be a constraint for accessories designed for home cabinetry for kitchens, etc.
Good luck...
Chuck