We went last May and did the trip with a company called SunDance Helicopters, and it was fantastic!
http://www.sundancehelicopters.com/tourpage.as px?id=311
We chose the Grand Canyon Sunset Tour and loved every minute of it.
They picked you up from your hotel in a limmo, flew you to the canyon (via the hoover dam and Lake Mead, we even saw a tiny speck on the rim which was the skywalk!) and then landed on the canyon floor where we had a champagne picnic under sunshades.
There was plenty of time to take photos of the magnificent scenery, and then the return flight was timed to take in the beautiful sunset and get back to Vegas just as night was falling. They call this the Twylight Tour and it is a tour in its own right, but on the Sunset Tour they combine the two so you get the iconic view of the city at night. Then it's back to your hotel in your limmo ready for a night on the tables!
The whole tour takes approx 3.5 hours door to door and was under �450 in total. We heard an american couple saying they'd spent almost 14 hours on a bus to save a bit of money doing the tour!
If you're thinking of doing the skywalk some say it's not worth the money so check it out before you go, I think you pay for the journey and then have to pay another $70 or something to go on the walk, and I seem to remember you're not even allowed to take photos from the walk!
Hope this helps.