I need to start shopping local banks/credit unions to secure financing for my (hopefully near future) rental property purchases.

As far as getting a pre-approval, I would reach out to every local bank/credit union that you have around you and get an understanding of what they're looking to fund.  

IMO, FICO scores are so generic that while you can filter out, you may also be throwing the baby out with the water - - missing tenants that are just recovering from messy lives.Before pulling a CR/BG report, I vet the previous landlords, employment and income, thus saving expense for a non-starter.Then, the CR (if you get a real one from Trans Union/Experion) will have all the accounts and their payment histories.  

@Tony Santos I think your best bet would be to call a couple local banks or credit unions in your town.

They exist, so there is a chance you can find one, though not likely.Try and get cozy with all of the commercial lenders at your local banks/credit unions.

I am trying to make an appointment with the loan officer at my credit union, but I'm wondering if there are other tips or suggestions any of the more experienced/informed members might be able to send my way.  

Try credit unions.

Local bank mortgages/Credit Union loans taken out in 2013-2014 on this structure will be around the 4.5-5.5% rate mark, at best. 

You will find "portfolio" loans at your local credit union or savings bank.

I am looking for an investor friendly bank that writes mortgages in house (my current credit union in NJ has stopped).I currently have 3 mortgages, so I'll be hitting magical number 4 soon after my move and need to get creative unless the lender is more lax.