I believe the RMAF needs to rationalize what specific types of Fighters they
really need in the future and then scrap the rest. They currently operate no less than NINE different Fighters, Strike Fighters, and Advanced Jet Trainers (single & tandem seat Mig-29s, F-18D's, Hawk 200s, Hawk 100s, F-5Es, F-5Fs, a single RF-5E Tigereye, and MB-339s.) Talk about a logistical nightmare!
The last four types (F-5E/Fs, RF-5E, and MB-339s) are totally redundant to their needs and could easily be sold to other nations who already operate these respective types.
Since the F-18D Hornet is no longer in production and the F-18F Super Hornet lacks sufficient range sans AAR, I'd recommend the SU-30 MKI for the long-range overwater anti-ship and overland interdiction roles. Team up with Brazil and some European defence contracters and upgrade the SU-30's with latest advanced electronics, HUD, Attack/Nav. systems, etc so they can interface with French, British, German and Russian made precision ground attack/anti-ship weaponary. This way, the RMAF doesn't have to rely on a single source/nation for hardwear in a crisis. Two squadron of 18 each deployed from two different bases for survival and overall coverage particulary in the South.
Upgrade the Mig-29s to SMD standard (if this has not been accomplished already) to be utilized in the medium range all-weather Interception roles and arm 'em with the latest Russian BVR missiles.
Seriously take a look into procuring the JAS-39C/D GRIPEN and it's outstanding integrated data-downlink info system. This is the most advanced of it's kind in operation in the world today. The Swedish were the first Air Force to field one and now the rest of the Western nations are playing catch up. Interface this with a modern AWAC's system such as a cheaper EMB-145 AEW Jet or if funding is secure the much more capable (and expensive) 737-700 WEDGETAIL AEW Jet would give the RMAF and outstanding defensive and offensive warfare capability. A minimum of 4-AEW Jets are needed.
Finally I'd procure 5 to 8 A-310 MRTT air-to-air refueling tanker jets and upgrade the existing KC-130Hs for not only fixed wing AAR but also for a future
Combat SAR Helicopter acquistion.
Their ORBAT could look something like this:
SU-30 MKI - Two Sqds total = 36
JAS-39C/D GRIPEN - Two Sqds total = 28/8
Mig-29SMD/UBM - One Sqn total = 14/4
Hawk Mk 100 - Three Sqns total = 54
EMB-145 SA AEW - One Sqn total = 4
A-310 MRTT AAR - One Sqn total = 6
KC-130H AAR - One Sqn total = 4
Strategic Airlift would be either turboprop A-400Ms or IL-76 Candid Jets totalling a dozen. The turboprop AAR could possibly be replaced with the
KC-130J-II STOL version to eventually operate from an air base in the Sprately's (future Oil prospects) providing coverage for a small detachment of either SU-30's or Mig-29s.
Tactical Airlift/Regional if the KC-130J-II STOL were procured the logical choice for spares/logistical reasons is the C-27J SPARTAN sharing the same engine, propeller and transmission as the C-130J series aircraft. About 24 would be ideal with half based permanetly in the South.
One Squadron of HAWK Mk 100's fitted with nose mounted laser designators could provide close-air-support in anti-rebel operations for much lower cost than a supersonic MRF can.
Some sort of long range Maritime Patrol Aircraft needs to be procured wide choice here. The RM Air Force could opt for 'surplus' P-3C Orions ($12,000 per flight hour) or the new MPA version of EMB-145 Jet or IPTN 235MPA's or whatever. About 10 are needed given the immense size of EEZ to patrol that would provide two squadrons of five MPA's each in two different locations.
A new Search & Rescue Helicopter is also urgently required. I'd look into procuring a High-Low mix capability of say 8-EH-101 MERLIN's for long-range/high casuality capacity at two different air bases. And for the short-to-medium range either 16 AB-139's or Bell 412SP's in detachments of 4 each at all the major air bases for maximum SAR coverage. One air base would have more of each type for conversion training so the total number of each would be slightly more.
Lets don't forget here that some type of Sig/Elint aircraft platform is needed as well. I'd go for a twin turboprop in the class of Beech 1900D, King Air 350, EMB-120ST or similar. This type could also be utilized for Multi-Engine Training, Photo Survey & Mapping, medium-range VIP, etc. Turboprops are more economical to operate than Jets especially at these inflated Oil prices!