[bienchen]

I'm have been an international student in the US on an F1 Visa for the past 8 years and will be attending graduate school for the next 6 years (PhD). Since August 2011 I've been employed full time (12-months CPT and 12-months OPT post master's). My PhD program is located in one of the cheapest areas of the US and it makes sense financially to buy as opposed to renting.
I will be able to put 20% down and I have an excellent credit score (795) and, of course, I have a 2+ years work history (was a TA in my master's program for 2 years before I started working full-time - altogether almost 4 years bv the time I'd apply for a mortgage ). Additionally, my PhD program guarantees funding for 6 years.
I'd like to know what I need to watch out for when applying for a mortgage.
What are the official regulations for giving a mortgage to non-resident aliens?
I know that ultimately a lender can exclude people on whatever basis they feel like, but I want to be prepared for at least the most common scenarios. I know it's easier to if I have at least an H1B visa, but what about my specific situation (not many people can say that they'll have a guaranteed income for the next six years)?