Hi there,
I did the Avtech course a while back and although it was very good , it lacked a little on the technical side of things. One thing about Avtech is this...you'll find the cost of the course hard to beat!! For £1000 or so you can get a city and guilds cert in flight ops which will get you interviews..believe me. When I had done the course I then went to the US to do an FAA dispatcher licence. You can use your experience from the Avtech course to shorten the time and decrease the cost of the FAA one. Sheffield School of Aeronautics are the leaders of the pack when it comes to FAA dispatcher training. They even have the test prep for free on their website, most other schools make you buy it and then waste your time and money trawling through it so that you emerge knowing only slightly more than when you went in..there's one in the "Lonestar State" that springs to mind..hint hint. Also with the exchange rate between the $US and £STG/Euro so good right now you'd be mad to pass up the chance to do the FAA.
Whichever route you choose, Good luck.