In reply to Juju:
We did the As Sab (Balcony Walk - W6) last year and the Via Ferrata. We left our car in the wadi above the end of the Via Ferrata and walked down the road to the start in the village of Al Khitaym. Route finding on the walk was straight forward except for locating the start of the Via Ferrata. You need to find the pool above the abandoned village and then take the path heading up the right. The Via Ferrata was in excellent condition. We also did the Snake Gorge Via Ferrata but we had problems with slack wire on the first zip traverse.
For a video of the balcony walk and the Via Ferrata see:
For video of Snake Gorge Via Ferrata see:
For any more help you might try the Oman climbing forums:
http://www.omanclimbing.com/forum/index.php
Martin