Congratulations on landing a medical residency in Boston! I used to be involved in medical research and it's a great area for residents. I'm familiar with the issues of relocating fresh out of medical school.
I have lenders who would have no problem as long as you have an employment contract or letter. Your years of medical education count toward your employment experience.
I live in Watertown (borders Boston) and have a mortgage office in Natick - I would be happy to chat or meet with you to further discuss your needs.
Let's keep in touch!
I am a practicng attorney in Boston, and i do a lot of purchases for physicians in your position. Contact me at firstname.lastname@example.org or 781-849-5906 and I can let you know about some viable Boston options. I just closed a 95% loan to value laon for a physicain and her husband using one of my sources.
When I come up with all the perfect scenerios of buyers who would fit a "rent to own" situation, the main one I come up with is a situation like yours. It creates a situation where many sellers are not familiar with it, so it may be too limiting of homes that fall into this category.
Here is how it works:
You rent a home with a prenegotiated purchase price for 6 months or some other future date. The contract comes with a non-refundable deposit also. Do inspections, negotiations, etc as you normally would. Sometimes part of your rent would be used as your down payment, but in your case you don't sound like you have a lack of down payment funds.
After you start work, go get yourself a mortgage and close on the property.
Hopefully this unique purchase will not have to be used and a mortgage company can get the job done, but lenders are tighter than ever, and it may be tough.
I could also apply for an exception directly from fannie mae to offer a 30 year fixed rate productr but I would not be as confident that the exception would be granted.