Not sure about ITIL, there are plenty of opportunities for Prince2 and APM quals both in service and as resettlement. CTP has a list of available courses and start dates, this link is to the Aldershot 3-4 week full project management courses covering Prince2 foundation and practitioner as well as membership of APM LINK
Yes, as ChieffTiff has said you can do Prince2 under resettlement. You can also do it at a DELC and you can do v3 ITIL via both methods.
Despite my initial cynicism - I hate paying for common sense (IIP which always seemed to be too much like the div system) - all my staff undergo ITIL foundation training and its makes a difference.
Civilian employers will like it too. As with Prince2, if you do the courses be prepared to back up the certificate with experience otherwise potential employers will be wary of you unless you specifically point out you have recently completed the course to indicate your potential. We've gone from the days of paper MCSE's to paper project managers, employers are wary.
I have been the operations manager now for two large outsoure companies and both have employed ex service people as a preference. The big drive now is ITIL and and if you want to get into management then get PRINCE 2 and go down the project management route instead.
Honestly, you cant go wrong. The current crop of project managers I work with are
1 x ex RN officer
1 x ex Tiff
1 x ex pongo
Guess how much stick the ex 2 ringer gets !!
5 out of the 22 staff in my teams are currently ex forces also.
I recently undertook my ITIL red badge and although it was a pain, it was well worth the effort.
Hope it helps those thinking of resettling and looking at what retraining to do.