A bit out on yer measurements there Cazatou - Saiq is at 6300 ft amsl (should know, was part of the SOAF March-and-Shoot team that climbed it from the bottom of the main wadi). Don't seem to remember the Skyvans having any probs, and our 205s could still lift more than a Wessex at that altitude on our way up to the hill villages at 8500 ft. Jebel Shams - the top of Jebel Akhdar - is plus/minus a very few feet of 10,000.
As for the war zone only going up to FL100, that was before SAM7b appeared on the scene - I believe (teeteringhead will be able to confirm) that forced things up to around 12000 feet agl.