Prices are currently high, so we’re looking to educate ourselves on how to find a good deal.

Most likely I can pocket 50% of the rent for paid off property.  

Ask to speak with some of their current owners and current/former tenants.

@Chris Morris have ALWAYS seen bad "deals" from rookie wholesalers that really don't understand what they are doing to provide value to the industry.It's getting worse because the real estate market has recovered from the 2010 Crash, yet many are still using tactics & methods developed during this time.Everyone in the industry needs to go back and look at what was being done BEFORE 2010 and start using those methods, updating them with current technology.

Talk to all of them and see which ones you like, fly to town and meet them, look at some examples and numbers on current deals. 

If I had a good tenant and they continue to be a good tenant, I don't care where they legally get their money from.I agree that most S8 do not meet my criteria even without considering the source of the income.However, we have another policy that also works against S8.  

Done multifamily, SFR, STRs... and finally found the niche that I love the most and believe has the most potential for decades to come.

Switch Lenders: I’m currently working on refinancing (six other properties), so I’m thinking maybe I should take everything to another lender who might be a better fit.  

As far as rate is concerned, you can usually go about two points over the current rate (less closing costs for a seller financed deal so there is no real expense there) You need to make sure the borrower can cover that.

So I would suggest keeping your STR property geographically close and doing as much as possible to keep your profit% high as possible.As far as the actual house you use, I would just say - be honest, be fair and strive for the best area, most amenities, cleanest house, best communication, and any other extras you can get.