I can only speak from the UK angle, but you are right in saying the air force is more 'posh' - or to put it more accurately, the average level of education of individuals is higher in the air force than in the army... it has to be, because everything, from flying to aviation engineering, is so technically demanding. (That is not to say that the army does not have similar demands in their own technical/flying branches - but I'm talking overall.)
To give you some idea, in the days of National Service, to be trained as a radar technician in the RAF you had to have a minimum of a Higher National Certificate/Diploma (but preferably a degree), in an engineering/science/maths discipline. However, for National Service in the army you simply had to be physically fit. Today, you will find many RAF non commissioned members with higher technical qualifications, including degrees, and all commissioned officers have to be graduates.
Air force bases tend to be very pleasant places on which to live, and are usually situated in beautiful countryside. Incidentally, I don't think you would have any problems in making friends in an air force environment because you would be with a group of people like yourself, and something called 'Esprit de Corps' will be present. This is rarely experienced in civilian life; it links you very closely with your colleagues and with the service as an entity - and it will remain with you even when you return to civilian life.
So think very carefully what you want to do in the services and make sure you examine every aspect as closely as possible. Ask questions, speak to people who are in the forces, visit service bases (don't forget the Navy either!), read books by people who have served in the air force/army/ navy, and make sure you choose a service training that will help you in your career on returning to civilian life.
Anyway, if you join up here's wishing you good luck!