Details for joining can be found at
http://www.durham.ac.uk/nuas (inc links to all UASs)
<b>FD</b> You cannot join a UAS as a pilot at your age, as you need to be at Cranwell by 23.5 years old. Very few non-pilots are recruited nowadays.
<b>rahaney</b> You have to mention PPL to them: not disclosing flying hours will get you in serious doo, plus they will refuse to sign your logbook when you leave if you do not.
In general don't bother with UAS if you are only going to use them for hours: you will not enjoy it. If you seriously want to give it a look for two years, then fine, as this is what it is for.