I would second with Rahimdad advise than Shadow79, just because you need a specialize masters degree in dealing with those small suspension shops in sharjah, as 99% of the time they will sell you something lemon proving that you are a moron.
If you want a proper job, find what fits best on your model of fortuner and change the all 4 sides with proper upgraded version. Check with known brands like: Ranchos, Tough dog, Rough country, Old man EMU, Kings, etc.
These proper upgrade might cost you more but be rest assure that you will not topple or get broken suspension in desert when you needed them most. I fixed broken suspension once in desert and spend 4-5 hours in heat and later realize that owner has got one of those used suspension from shj shops and it was misfit as per vehicle weight and that's why it broke in second minor jump.