Need advise - financing larger (4+) multi-family properties

Hello

I have a pre-approval with a conventional mortgage lender for purchase of a property that is up to 4 units only. I am looking to invest in the Pittsburgh market. I am coming across some deals that have 5-8 units that have better cash flow and appealing. Any recommendations on lenders who can finance these properties? Also, how much downpayment will be required for these loans and what does a typical term and loan processing timeline look like?

Thanks a lot in advance