I am Argentine and married an American citizen 13 years ago -- things may have changed ever since. We got married in the US and we lived there. I had my 1st appointment at the IRS four months after we started the paperwork. We contracted an attorney. I was given my green card short after that.
If I stayed abroad (outside the US) for more than six months for a good reason I was able to keep my legal resident alien status. The point is, the "good reasons" are not listed or written anywhere.
As a matter of fact I stayed in Argentina for little less than a year after I got my green card. When I got back to the US, I was interview at the airport by three IRS officers. I was granted my legal resident alien status.
I'm not sure though if you can obtain the green card / residence while living abroad.
Best of luck!