We have around 10 guest coming from UK and we want them to spend a night in the desert.  Please can you suggest where we can hire big tents or any other idea.

I would suggest you contact Adventure HQ and ACE hardware stores who both have rental sections.  My other idea would be to ask around your friends as a lot of expats have a tent stuffed at the back of their cupboard (once used!) that they would be willing to lend you.