LP vs. gasoline. New generator in old Motorhome.

Hello, I have a 1996 Southwind. At the end of the season last year, my 22 year old Onan bit the dust. I believe the alternator bit the dust. Luckily, there is an Onan repair center just a few miles away. If it cannot be repaired for a reasonable price, I am going to have it replaced. I am leaning toward the replacement as the generator burns oil and is prone to stalling on a heavy load.

My question is this: if I replace, should I choose LP or gasoline? The current generator is set up for gasoline. It draws from the 75 gallon fuel tank that is shared with gas guzzling Ford 460. Running the generator drops my fuel mileage by about 1 to 1.5 mpg. This is significant when I am only getting 5.5 to 7 mpg to begin with. I am considering switching to LP as the motorhome has a 24 gallon LP tank on board. This would extend my driving range, which I am happy about, but has me concerned about finding a place to refill the LP tank. Dual fuel would be the best of both worlds.

Any advice?