Buying a house to rent to my in-laws

[Rachel Leonard]

My in-laws are moving to the US from another country.  They would rather not go through the paperwork hassle of purchasing another house here themselves; they would prefer that my husband and I purchase a house in our name and they will rent it from us.  They are providing the money for the down payment and have in fact already transferred $100K to an account in my husband's name.  We already own a primary residence and vacation home, so this will be seen as an investment property.  How should I think about getting financing?  My understanding is that a gift cannot be used as a down payment for an investment property, so my thought is to wait 2-3 months before applying for a loan, to season the funds.  I do have sufficient cash of our own in our bank accounts to show we could cover the mortgage for ~6 months if it was unrented.  Any other thoughts/ideas?