commercial vs residential loan in South Carolina

[Robert Barnes]

I have the chance to purchase a 4-plex in South Carolina.  I need advice about if I should use a 20% down payment at 5.25 interest commercial loan or a 20 % down payment residential loan at 4.75% interest rate.  I hear that the residential loan make take longer to get a approve and require all the units to be rent ready.  The commercial loan will be a lot easier to get. However the commercial lender will only do a 20 year amortization.