Sounds like a great trip Ash. With the Grand Canyon when i was there in 2014 we just booked a small bus tour which took about 4 and half hours to get there, think it left Vegas about 5 -5.30 am for the trip, There were a few electrical storms when we were at the Canyon so there were no helicopter flights at the time.
This is worth a look if you like some of the old history of Vegas. Don't think they were doing the night tours when i went in 2014
Welcome the The Neon Museum. We are the story of Las Vegas, and here you'll find spaces, signs and experiences that bring our rich history to light.
www.neonmuseum.org
Hoover Dam is worth a trip also, it is fairly close by so assume there would be tours there, the friends we stayed with drove us out there.