Here is a link to your floor plan
http://www.rvguide.com/specs/fleetwood/class-a/2008/fiesta-reg/34b.html1st off remove the bunks and make that into a computer room, reading room, etc, replace the jack knife couch for a better one with recliners, do other upgrades to make it as you want, as to the shower not sure what you can do there but just think outside the box it can be done and than you will have a custom motorhome..
You will miss traveling in a motorhome when you get to backing in that 5th wheel in a tight campground..