AS,
Couldn't possibly comment on being an FC (weps or systems) but I know I don't want to be one! As far as the ATCO job is concerned it's very interesting and varied (and becoming more so-explain later). The problem is that you get paid a LOT less than our civvy brethren. Generally speaking we work in a more demanding environment, not just because of the dynamic introduced by mil aircrews wanting to do what they want, when they want. But also through all the secondary and associated duties. Oh and the fact that we can go to war. In the last one, a lot of guys got sent out not just to do ATC jobs but also liaison jobs between the local ATC community and fast-jet operators. As an ATCO, you get commissioned into the Operations Support branch, not just as an ATCO, so there are a lot of different and interesting jobs out there if you want them. Brigade Air Liaison (BALO) jobs with the army, Tactical ATC, combat airspace management etc etc.
As far as liaison visits are concerned, your best bet is to ask your CIO to sort it for you. If you don't ask, you won't get. They should be able to get you onto flying stations to have a look around, stay in the Mess and all that. While you're there look at all the areas you're interested in. You might be able to get into one of the FC bunkers and depending on where you are in the country you may be able to visit London or Scottish centre to see the area radar side of the job. If you want any other hints just go into the search funtion on here, there are plenty of references to going through OASC. Enjoy and good luck