Also, remember that all F/A-18F can be converted to EA-18G configuration to provide the most powerful fighter borne EW aircraft platform in the history of war:
http://www.boeing.com/defense-space/military/ea18g/index.html
The following is the first paragraph for the link.
“The EA-18G, currently under development for the U.S. Navy, will be the cornerstone of the naval airborne electronic attack (AEA) mission. Derived from the combat proven F/A-18F aircraft, the EA-18G incorporates advanced AEA avionics bringing transformational capability for suppression of enemy air defenses (SEAD) and integrated air/ground operations.”
It states clearly that the EA-18G is derived from the F/A-18F. It does not state that an EA-18G can be created by converting a F/A-18F.
Embodying the necessary modifications by retrofit is likely to be difficult and expensive. Deploying some of the systems used on the EA-18G on the F/A-18F may be possible. If you want an EA-18G buy a new one.
It is worth remembering that in order to equip the EA-18G for the SEAD role, some equipment installed on the F/A-18F has had to be omitted from the EA-18G. So even if full conversion is possible, the resulting aircraft would loose some of the capability of the F/A-18F.
There may be a half-way house for the RAAF, if it does not want to buy dedicated EA-18G aircraft. It may be possible to include provision for some of the EA-18G systems in the new build F/A-18F aircraft. If the wiring is included during build, the equipment can be added as required. This could provide an enhanced SEAD capability, but not at the level of capability of the EA-18G.
The halfway house approach has some advantages, but also has a down side. If the enhanced SEAD capability is not included in the whole fleet two standards of aircraft have to be supported. If the capability is only included in a few aircraft, then there may be problems with aircraft availability and operational losses. A similar argument can be made for the acceptable degree of divergence form the standard US F/1-18F & EA-18G aircraft. If the RAAF aircraft are too far from the US aircraft then further developments may be difficult to incorporate in the RAAF aircraft.
Ideally if the SEAD “Lite” approach was adopted all of the aircraft should be built to the same standard. Unfortunately I think that the RAAF needs the aircraft quickly and must settle for USN specified aircraft. In which case the best option would be to purchase all of the F/A-18F aircraft to the same USN specification and buy a small number of standard dedicated SEAD EA-18G aircraft.
BTW:
Much of my career has been spent developing modifications to avionic equipment and integrating it with the aircraft.
I have found that the difficulty involved increases by the 2nd order power law for the number of configurations involved, multiplied by a 4th order power law factor taking account the distance between the special version from the standard version. The moral here is if at all possible stick with the standard version.
If deviation from standard is required then meticulous attention to detail is required. Even within the same block of aircraft there are often small changes in configuration that can be significant when developing modifications. (e.g. wiring that should be connected A-B-C is connected A-C-B, work the same, but if the modification instructions says, remove link from A-B and connect A-D, the maintainer is stuck because there is no link between A & B, instead there is a link between A & C.)
And finally a little saying, “Configuration Control, like virginity, once lost is rather difficult to retrofit”.
Chris