If I were you I'd forget about JAA if you're going to be in Houston for 18 months. The FAA ticket is issued on the spot for no additional fees, there is one "online" exam to take, and you can use its privileges world wide. If you feel you really want a JAA one on your return, it is a piece of cake to transfer if you have > 100 hours (can't remember exactly what, airlaw paper and RT or something silly).......