Ironically, I think the DOJ nonsense is backfiring on their intentions. 

if you think there is more equity there you could have an appraisal done… but some lenders will not re-evaluate a recent purchase for a set period of time… they will just stick with the old purchase price as its value (varies by lender) unless you can show significant improvements you did to justify a higher price. 

Are there if any sites specifically filtering seller finance deals? 

I put some numbers below into this Rent or Sell calculator.https://www.narpm.org/members/resources/rent-vs-sell-calculator/ESTIMATES ON ROI (15 year time frame)at 5% Appreciation would profit $100K if SELL nowat 6% Appreciation would have $3,500K more if KEEP and sell after 15 yearsat 7% Appreciation would profit 122K if KEEP and sell after 15 years(Assuming a conservative 6% ROI on money invested from sale.)NOTE: The property appreciated 10% in the last year so I’m thinking 7% over the next 10-15 is reasonable.DETAILSSale Value: $520,000 (Best guess)Paid: $437,000Original Mortgage: $415,000Mortgage Balance: $380,000Interest: 3.375%Monthly mortgage: $2,899Mortgage Difference: $1064Annual Taxes, Insurance, HOA etc**: $20,345**$13,865 (Non Homestead tax) $4,680 (HOA) $1,800 (Landlord Insurance)Monthly Rental Charge $3,500*Appreciation 7%Years to Hold: 15More assumptions used in ROI Estimates Above90% occupancy,15% capital gains charge6% selling feeRate of return on gains if selling now instead 6%Annual maintenance 1%Annual rent increase 4%$3,500 is slightly aggressive. unlikely I could get more.Thanks in advance for any constructive thoughts and comments!!!!

The reserve price wasn't met, but it's set very overpriced, and I don't think anyone would meet that price.The day after I won the auction, I received an email stating that the seller is offering all eligible bidders the chance to place another bid.

I guess it´s  also a duplex, I think as Jay mentioned it should be no problem to apply for another conventional one.

It's convoluted thinking, I know, but I didn't make up the rules, I just analyze them.

Based on our conversation, I think he could put down 45-55% of the PP

Also, I think a newer building would make my life as a landlord a lot easier since I don't have much experience and wouldn't have to worry as much about stuff breaking down all the time.

Before thinking of going for the 3rd one, which would be great if it goes as well as these two,  I need to fix my own house (personal) .