I had a nightmare getting dual purpose tyres in the UAE. I couldn't find anyone with Tourances, Trailwings or Scorpions or any other common option. Sandstorm were the only ones whose eyes didn't glaze over at the prospect of getting them, and they said they would have to buy them in. I ended up buying them from Australia myself and getting them shipped over. Luckily it was during the summer and I was happy to be off the bike for a few months. When I got them I had BMW fit them - big mistake. They fitted them incorrectly which almost brought me to grief when I got the death-wobbles mid-corner.
BMW are pathetic in the UAE. They are only interested in selling you a new bike or a $700 jacket - after-sales is an after-thought.
The Harley guy in Abu Dhabi re-fitted my front for free (a South African mechanic who actually rides) and he had nothing good to say about BMW in the UAE. I believe there is a Harley guy in Dubai that's as good.
So, my recommendation is to buy them through Sandstorm (or Harley D) and have the Harley guys fit them.