If I've got this right, you are wanting to spend $25,000+ remolding a $20K DP with 100K miles on it. When you get finished you will have a $30K motor home that is 15 years old with 100K miles that no one else wants... OK, that a few might want.
I'd sell it for $20K and add the $25K and find a 06 similar unit with half the miles and updated electronics. Sorry but I think you are going to throw good money into something that while it's served you well, it time to upgrade the entire rig.
If you decide to continue, then I'd start looking in the Amish area of IN (RV capital of the world) for shops that will have surplus items and more reasonable prices to do the work. Good Luck