Help with small(er) commercial multi family loan

First post here!  My brother and I have a portfolio under contract in Charleston, SC which includes a 14 unit complex as well as 3 duplexes and 1 triplex.  It is being sold all together as one package.  Purchase price is $1 million.  We would like to finance 80% and have as long of an amortization as possible.  This loan amount and the duplexes/triplexes being included seem to make this a tricky loan.  The total portfolio appraised for $1,285,000 earlier this.  Fully occupied and cash flowing.  Not planning on doing major renovations.  14 unit is class B-, other units probably class C.  We may want to sell off a couple of the duplexes/triplex.  Any advice on the loan strategy here?  I see that Fannie has loans starting at $750k but don't know how the duplexes/triplex affect this?  Seems like a refi in a year or less may be beneficial with the instant equity at closing.  Thanks in advance.