You have to be careful with what the dealer is telling you about the generator install. There is the Gen prep cost PLUS the generator installation. All generator installs are about 6K and add the gen prep for a total of about 7K, while this is a negotiable item you have to know how it is being priced. The there is a lot of confusion about what a gen prep is. This is what I discovered when I ordered gen prep and later installed my onan. In my opinion the 800 I paid for the prep was worth it.
1) sheet metal heat sheild and sound box
2) generator mount
3) Junction box and wire (routed) from Junction box to transfer switch
4) Transfer switch
5) Onan control panel
6) Onan control wires.
Then my $3750.00 (ordered out of Arizona no sales tax and no freight) LP5500 generator slipped right in. With only a few cuts in the floor of the generator garage for the air intake and exhaust, and a few access holes (dimensions and layout provided by Onan).
I had to buy a LP regulator, a hose to connect to regulator from a cylinder, a cylinder, and a common appliance hose. I did this because I wanted a dedicated cylinder. If you want to run off of LP system it is not necessary the plumbing is already there anyway. All this was about $100. So my total generator cost was in the neighborhood of $4650. And i walked away being very familiar with the system. I forgot to tell you about the $29 I had to spend on my tail pipe.
BTW, anyone who does such an installation is warned to find the transfer switch, and remove the lockout that keeps the transfer switch locked out of the generator default. Mine was bright yellow and I burned up my transfer switch by starting the generator without removing it. It tried to default to the generator and could not so it burned up the transfer switch.
As far as mickey mousing around general purpose generators, just buy what goes in it, increase the value of your rig and enjoy it. That is what you bought the rig for right? I have researched it pretty good and I will tell you it comes down to watts. How many watts do you need and how much do they cost. Nothing is free. Pound for pound and watt for watt, you cannot beat the Cummins onan that was made for your rig. So why not have it so that you can turn it on and off from inside your rig, you can install an automatic gen start that will automatically start it when your batts run down or the thermostat call for air-conditioning. There is mickey mouse, poor boy and professional, which would you rather have?
After all if all you want to do is charge batts and watch TV then put in Solar, its much cheaper and just as effective. A generator should run your whole rig and both air-conditioners all at the same time. So I guess what I'm asking is what are your goals? And what will accomplish those goals. I dont think that tent campers and other RVers will appreciate you watching TV with your general purpose generators running after quiet hours. Then there is national forest approved for spark arresters and noise.
I recommend a good clean installation of a quality generator big enough to handle your rig, if you cant do the onan install then get the Big Honda, but then you have a less than desirable installation. - good luck in your endeavour. I hope I have helped.