Where to find a 40 year loan due in 30?

I'm looking at purchasing my first house soon, since i think now is a good time to buy and it makes a lot more sense than throwing money out for rent.
My career is in it's infancy, and I'm almost done with school so I expect my income to go up a lot in the next few years.
For this reason, I'm interested in either a 40 year fixed loan due in 30, or just a normal 40 year loan and I'll make a lot of extra payments once my income goes up. This way I'll have cheaper monthly payments now and more leeway, and once my income goes up i can start paying more.

I can't seem to find many banks that are offering 40 year or 40 due in 30 loans anymore. Does anyone know of any that are, or have any idea of where to look for them?

Thanks.