We took our new Aspect to our stereo guy before our first camping trip, and we did go a little over the top. He put 4 4x9 speakers in the coach part and component speakers in the front (separate tweeters). You really need good speakers up front in the "van" area. You cannot hear the coach speakers while driving unless you really crank them.
Also, to get good sound, you need to use an amp to power the speakers. Amps are not just for high volume, you need them to give good full sound at low volume too, otherwise it sounds sharp.
There are lots of good small car audio shops around, most can set you up with something afordable that will suit your needs. If you are looking here for advice on what to do, you obviously don't know enough. Spend a few bucks and get it done right.
We did the same as triple602. The first was a Weekend Warrior 19' toyhauller. Quality was fine excecpt for a short somewhere that drained the batteries. We sold it for a Cross Roads fiver. The quality on that unit was horrible. It looked great, but within a year it was falling apart.
We had fuel problems (starving the gen), grey tank leaked and was inaccessible, wheel fell off (good thing there were 6), 30 gallon fuel tank would only hold 12, one of the 60 gallon water tanks could not be filled past about 20 gallons, and on and on. It sat on the dealer's lot for over a year after we traded it in.
Our next was a Winnibago Aspect. We have had it for over 5 years / 30k miles. Zero problems so far. The quality of Winnibago is way beyond some of the others. I suspect you could say the same for Fleetwood. There is a reason these guys have stayed in business for so many years.
I neglected to mention, my other thought for the lights is switching to fluorescent. The double fixtures are about 3" x 12", I am pretty sure there are fluorescent fixtures of similar size.
Oh, and we do a lot of desert camping and my wife loves to read, so we need something with good light and low power usage.
I am considering changing out the interior lights in the MH. Its a 2007 Winnebago, but the lights are all the old school bayonet style bulbs. I have about 5 double fixtures and then some singles and other styles. I am wondering, at least for the double fixtures, if I should use the LED style bayonet bulbs or replace the whole fixture with something that uses LED.