It probably just depends on what you like to drive
I have driven many of these roads in a VW New Beetle. In my experience, the roads have been paved and in good condition. My car is fairly low, with little clearance, and I don't recall it ever being a problem.
I don't rent cars enough to have experience with this myself but, according to others here, you can't take a rental vehicle off-road so this would really limit your need for an SUV. So I really think you should rent whatever vehicle fits your budget, is roomy enough to be comfortable for you, and that you would enjoy driving the most.