The most sought after qualification would be an FAA Dispatchers course. Once you have this the world is your oyster !!! Only trouble is you have 2 spend 4-6 weeks in the US
Plus it costs a fair amount 2. If you invest in this you will earn the amount you spend out in a couple of years. The most admired FAA school is
www.sheffield.com
Also have a look at
www.aviationjobsearch.com under operations vacancies and SV Airlines have a job ad for a FAA qualified dispatcher and the starting salary isover £27000. Much better than the 16K i used 2 get at LGW.
I enquired about the ICAO course at GLA and am waiting untill the certifacte you receive on completion of the course is actually endorsed by ICAO.