Get 4WD...at that time of year you'll probably need it. It can also open up more interesting destinations. For the piece of mind alone it will be worth it.

We just returned from a trip to southern Utah (will post a trip report soon) and rented an SUV from Dollar in Las Vegas for less than $400 for 11 full days. We thought it was a great deal! Would suggest an SUV, particularly for travel in November.