Every job in ATC is different. Don't imagine that because the Area course is longer that it is harder. When you get to your unit it could take you a year to validate. Area control is very complex; Approach Radar may not be so complex but requires long periods of high levels of concentration. I've seen very competent approach controllers fail to make it on area, and vice versa.
Whether you go for aerdrome or area is up to you. Why did you want to work in ATC? If it was to be close to aircraft then you should go for aerodrome. If you do manage to get into the tower at Heathrow you'll see what I mean! It will blow your mind. On the other hand, if radar control fascinates you then area or approach is the option to go for.
Of course, you may not get what you want so be prepared! I've done most ATC jobs and thoroughly enjoyed every one.
Best of luck with whatever you get.