The advice for you to "do a short sale" is the first mistake.... If you are not in some type of hardship or financial difficulty, getting the short sale approved is going to be tough. Simply stated, the bank may "let you" do it.. they may not release you from the balance that is short. It is not that easy to do and it could hurt anyway,
I would tell you to talk to a mortgage professional regarding the rules on relocation with an FHA loan. There may be some type of relocation and being able to rent type clause.
I hope it works out for you! Good Luck!