The Grand Canyon is a spectacular visit, as is the Hoover Dam. If you choose to stay overnight at the Canyon, this time of year you should have little trouble getting a room at the Bright Angel Lodge. It is the less expensive of the two hotels on the south rim and very quaint. I like to wake before dawn, go to the larger hotel's, El Tovar, grand breakfast room for a bite while the sky warms and brightens out their huge windows and then walk the trail to see the sun rise. Bundle up!
In Vegas itself, Las Vegas Guns has some fun full auto rental packages. They're pricey but fun, especially the M79 ' blooper' grenade launcher. The 40mm round is loaded with something like 20 .22 LR cartridges in a matrix and they fire simultaneously, horizontally, at the target.
Good luck, have fun!
