The Sultan of Oman's Air Force had a variety of aircraft available, more of the same on order and were contemplating ordering further aircraft. The Dakotas were no longer used.

These figures were for the 2nd May 1972
Type Held On Order Contemplated  
AB 205 "Huey" 7   7 Image
AB206 Jetranger 4   2  
de Havilland Beaver 4   1  
de Havilland Caribou 2 1    
Short Skyvan 8 2 4 Image
BAC Strikemaster 9 8 1 Image
Viscount 3   2  
Source : Public Record Office  DEFE 13/779
The two types of RAF aircraft most often seen at RAF Salalah were the Lockheed C-130 Hercules (XV305) and the Hawker Siddley Andover.  An Argosy was also sometimes seen.
It was decided by BAC that each country of sale would have its own variation or mark of Strikemaster. The Saudi Arabian Air Force were the first nation to place an order, for the Mk.80 version. This Air Force turned out to be the main export customer, they ordered 47 examples in total, spread over three batches, and were delivered between 1968 and 1977.
The Air Force of South Yemen acquired four Mk.81 Strikemasters in 1969, and Mk.82s were delivered to the Sultan of Oman Air Force around the same time.

extract from "Jet Provost Heaven"

Currently SOAF have a number of F-16 fighters and in December 2011 ordered a further 18 rather than the BAE Typhoon to replace its SEPECAT Jaguars.  Perhaps UACVs based on futuristic BAE "Taranis" technology rather than something designed in 1976 might have suited their purpose ?

 However I must confess that I still have confidence in penicillin and that goes back to 1928 ! - The penicillin not me....

Oman was considering the purchase of either Eurofighter Typhoon or JAS 39 Gripen aircraft, but on 21 December 2012 a £2.5 billion deal was signed in Muscat to supply RAFO with 12 Eurofighter Typhoon fighter jets and 8 BAE Hawk Advanced Jet Trainer aircraft.