If you are self employed, you may run in to challenges for several reasons. One being the risk that your self employment income will not be substainable with the relocation.  The other would be determining how the numbers correlate to income in the United States. 

But, if you can show that you have been working as an employee while overseas for the last two years and have now transfered or gained new employment in a similar industry, the fact that you were not in the states should have no bearing on your ability to obtain financing as soon as your new employment has started. Typically the timeframe is set so that you cannot close on a purchase until after your first paycheck has been received.