Br-:
I did read your reply. It sounds like you are falling into the necessary "fix it yourself" category of those of us who worship a lesser motorhome quality control deity!
As far as the stereo goes, I put a 200watt Kenwood cd/fm receiver in place of the standard Sanyo stereo tape player. It seems to have plenty of power, but I am somewhat disappointed in the bass, even though I replaced the front speakers. I don't think the factory baffles give enough "reflex" room for good bass. I am going to also replace the rear speakers at some point, since I am a little hard of hearing and like to "feel" the low notes. I do NOT get into the room sized speakers/amplifiers/changers thing, but like to hear the full range of sound. Just about all the aftermarket brands (JVC, Pioneer, Sanyo, Kenwood, Sony, etc.)have many models that will fit easily in the space. You will have to take out the "cage" that the unit fits in, but that is easy, and the new ones will have their own mounting hardware, and I doubt you will need any adaptors. Just some simple soldering skills (or solderless connectors - I just prefer to work with solder). It took me about an hour to make the conversion.
I have concluded that some things are better done by me, than to wait on the dealer. They are very cooperative, but they are 50 miles away.
Your unit is less than 1000 lbs heavier than mine, so you probably are getting spoiled by the stability of carrying less than 9000 lbs on a 12,300 lb chassis. You owe yourself driving some other motorhomes, so you can see how much more stability you have than most.