Synovus and Regions had an appetite for this kind of thing in the past, but the fund I worked for had about $100m in assets at the time. Some small, local banks may have an appetite for this, but it literally varies by the bank/risk committee members and the only way to find out is in-person conversations - I dont know of any particular banks offhand. 

Typically, this kind of lending from banks/depositories is as a secured facility at the portfolio level and structured as a warehouse line. I havent seen these get approved when the total portfolio was less than $20m or so because banks usually wont go over 40-50% LTV on the portfolio and it takes a lot to underwrite these. Also, since this is effectively more CRE exposure, there might be an extra headwind there as well.

What I have seen in the past with this kind of thing is a warehouse facility that is used to fund the origination, and then the note is quickly sold either to an SPV consisting of raised investor capital, or to another third-party investment fund/bank that buys for yield, or securitized into a private label mbs/cmbs. The play for the originator entity is the points and fees - usually the asset itself (the note) has to be financed with equity capital rather than debt because the spreads are too thin to lever up unless you have a significant portfolio. Finding a bank that will finance a buy and hold small note portfolio is kind of a unicorn in the note world. 

@Chris Seveney runs a mortgage note fund and has likely come across this. He might be able to add some color.