How many people traveling?
For $40,000, and 3-4 times a year, gas is your best choice. The "house" part will be a lot newer and maintenance will be less. If the front engine is too noisy, it's easy to add sound proofing to the engine cover.
The other thing about a newer MH is that there will likely be more/bigger slides.
We use ours for several short trips a year and one long one. I added sound insulation to the engine cover and Koni shocks to the chassis. It is as quiet (except under hard acceleration, easy to handle, and comfortable to ride in as the one DP I've driven.