my geography runs out at the end of my road, but i would suggest doing whatever end is close to the hoover dam (thats what i did)
i did a helicopter tour with my parents and it was the highlight of my trip to vegas. cant remember which tour i went with, but i got a nice long flight, a bonus view of the hoover dam, a pilot who loved rock music from guitar hero 3, a landing in the canyon and a champaign picnic thing. on the way back we had a cheeky flight down part of the strip too.
if your worried about getting airsick, then really dont be - i have been airsick most times i go in a plane (especially at landing), and carsick any time we go up and down any hills, but the helicopter was as smooth as silk, and i was perfectly fine
its really gonna annoy me now, but i cant remember who we went with.
ps, try and get the front seats on the flight towards the canyon - its the best seat in the house.
also, you are totally right, the skywalk is a complete waist of money. the pilot said to avoid it like the plague - your not even allowed to take photo's