Were just bought our first 5th Wheel. Previous RV's were truck campers.
We went with a Grand Design 2930. You can access the fridge, the bathroom and the bed with all 3 slides in. That wasn't a big selling point for us but it is handy running in to use the bathroom or grab something from the fridge. We choose this brand after spending considerable time on several brands owners group forums. FWIW people seemed happier with the after sales service the company gives them. We purchased ours new at 30% of MSRP + T&L
Some of your other points:
Backing up. I am no expert having only towed ski boats in the past but haven't found backing up to be an issue. Ours is 34'-4" pin to back wall. Take the trailer to an empty parking lot and spend some time with some cones. There are some good videos on YouTube with some tricks. If possible have a spotter and work together learning to communicate. Typically when I see couple struggle to back their trailer in it is due to poor communication.
Generators are often an option. It was on ours but we chose to go without. The built in propane generators are usually expensive, noisy and heavy. Many people opt to go with a quieter inverter generator and tote it along in the bed of the truck. We went with a large solar generator but that's not for everyone due to cost. We also have a small 2000 watt inverter generator that can supplement the solar if/when needed.
Hooking up. I found this to be much easier than loading our truck camper. I just look over my shoulder out the back window to line up the kingpin. Super easy. You will need to get out and adjust the height of the kingpin once you are close. Again many good YouTube videos on this subject.
Fueling. We have ordered a combo tool box transfer tank. Our plan is to buy fuel where it is the cheapest and hopefully we can coordinate that when the trailer is disconnected. Fueling on the road with the trailer is usually pretty easy. We will be able to go over 1000 miles between fills. Use an app on the phone to find truck stops where lanes are wide and approach and departure lanes are straight.
