Of all the Middle-Eastern airlines, Qatar is the only one that is officially rated 5-star by Sky Trax.
From experience, Etihad also offers an excellent business class product – far superior to that of Emirates and Gulf.
In fact, Gulf Air is in financial difficulties and so I would be very wearing in booking anything with them, especially if it is for quite far in the future. Booking with a credit card is also a good way to protect yourself as well as taking out travel insurance at the time of booking.
Emirates, Etihad and Qatar are the airlines I’d stick with and if you have the choice – Qatar and Etihad business class over Emirates is the way to go.
Ask for prices on any of the airlines – we should hopefully have some good competition here so that you can find the best fare. I had a companion First Class fare with Emirates the other day (London-Maldives) for roughly £2200 per person!