Shame about the Visa thing. GA flying in the States can be good, but it's best at Vegas. there are so many things to do and see, intersting palces to visit - and the scenery...! The Grand Canyon, Sedona, Bryce Canyon, death Valley and the West Coast. You just can't beat it. I'd rather fly there than Floida anyday.
If you have a day's 'sightseeing', may I suggest a tour up the Canyon, perhaps landing at Grand Canyon National (6500' amsl) where you can get a bus or taxi to the rim. Or perhaps, fly half way up the canyon, Turn around, fly out to the west to Death Valley, land there (270' below msl) and stop at the visitor centre, then home. you may need a refuel stop at Boulder, but you can take in the Hoover Dam on the way there. I did this last trip with my Mrs Winterland last year - marvellous! Total time 4.30 in a PA28-200R, cost about $100 an hour, but more dual probably.
I've flown at North-town many a time, and Westair is the best of the bunch. A good fleet (lovely fleet livery!) good instruction, good attitude and good facilities.
There have been no flying clubs or GA hire operators at McCarren since 9/11. There are also clubs at Henderson to the south. Sport flying (gliding and aerobatics) can be done at Jean 45mins south of Vegas.