keep in mind that interest paid on a mortgage is TAX DEDUCTIBLE (taxes are the things that the government charges you when you have a job, a concept foriegn to many career students like ourselves), so the financial implications of home ownership are not always immediately apparent.
a word about new homes - i have just sold the house we bought brand new before med school, and am moving to a 24 year old house for residency, and couldn't be more stoked. remember that the vast majority of new homes come with little or minimal landscaping, which is way more expensive than you probably think. and even if landscaping is included, think charlie brown's christmas tree. i am leaving scorched earth behind and moving into large mature trees and shrubs with actual roots. personal prefernce of course, but keep it in mind.
also, new houses invariably have problems of their own because they settle. wood dries and twists, foundations sink into the freshly graded earth, etc. also, tract homes (assuming that we are not talking about fat custom homes just yet) cut every possible corner behind the drywall. it's the american way, and we all know it. of course the appliances, wiring, water heater, AC, etc are new and not likely to give you problems like in an older house. just know that there are just another set of problems to consider. 3 doors in the house we just sold have not shut for 2 years, plaster cracks, cheap vent fans, to name a few.
lastly, the deferment rules only apply if you are going fha, which is not necessarily everyone. otherwise, if you are in deferment or eligible for forbearance for 12 months from loan application date, they do not have to count it into your debt to income ratio. and a word of caution about deceiving mortgage brokers about where the down payment came from - mine wanted a paper trail. they often don't mind gifts, but tell them up front if that's the way you are going. remember that you have an MD and a job now - get out of the unemployed student mentality that is trying to pull off a fraud to get you the financing you want.
cheers