Either way, if you are a U.S. Citizen it should be easy to document your income....start keeping everything that relates to income and deposits from foreign sources and keep them in file for your return to the states. This will ease the pain of trying to document your income.
Your first step should be to speak with a local and trusted mortgage broker, they can prequailify you at no cost, they will look at your credit plus your financials and let you know if there are any programs that you may quailify for.
Please see my blog for a list of tips and advice for getting a mortgage
PDS Real Estate