I think a 5th wheel toyhauler would be much better suited to your needs, for all the reasons listed above. You can modify and upgrade to your heart's content. As long as you maintain it, it will last a long time. Look for one that's 2-4 years old and well maintained. You will likely need to replace tires, add batteries, add solar if desired. But that will be much better than starting from scratch.
With a 5th wheel you can drop the trailer and drive the tow vehicle, you might not even want or need the toyhauler space.
Listen to Golden HVAC. He knows whereof he speaks.
