Our favorite is Oasis RV Resort. Excellent electric so fear of brown-out is not an issue. Great pool, nice grounds, good pet runs. You can go straight up Silverado to get to Henderson. Sam's Casino has a nice RV park, but it is more of a full hookup parking lot. They have a small pool, and the Casino amenities are about 100 yards away. Yes, it will be hot. I suggest getting reflective window shades (like the folding type for windshields) and plan of placing them on all windows. Also you can cut some foam to press into the ceiling fan vents. If you have an RV frig, don't plan on keeping ice cream in the rig. We have kids in Henderson and make that summer trip regularly.
Enjoy.