My only issue is the legalities of transferring the money.....my dad would sell me the property through the bank mortgage (he gets paid) and then he would have to repay-me my initial cash investment.

My experian credit is Fair but still slight below 600 ( won't apply till i'm atleast 620 for less interest etc) however it's full of thousands of debt repayments to bills that had been/or still in the process of being paid off (intentionally to raise credit) I'm also aware that Lenders (apparently) are more concerned with DTI, which in my case is a good thing as I make pretty good Doe as a Truck Driver (but my employment record is anything but stable which could hurt approvals, however to be fair Trucking Companies are not typical jobs, jumping company 2 company is very common in this industry) The multiplexes i'm looking at is a 3-4 units but they seem to range around  low200-400k, so i need an ideal amount of money I need to save just for the remaining amount the loan won't cover.

If they want to lend me $5K, $10K, $15K, etc. and then I repay with interest, what do I need to be aware of?

The property is unique, it was an older couple who had a contractor building them a custom home.  

But thats no different than my buddy who had his company repay his 15% of his loans every year as long as he performed a certain level.

I knew I wanted to buy and hold from the get go for a few reasons: Residual income that comes in whether I work or not, low transaction costs per asset, tax advantages during the hold and at exit, leverage and legacy wealth-building.The specific assets and methods of purchase under the b&h umbrella presented themselves uniquely dependant on seller needs and asset types available in my market. 

I have an unique situation of redeeming an inheritance and I am running into issues getting to be able to finance the property

Obviously, this benefits me more than the seller, but I'm curious what other people think of this unique idea. 

This situation is super unique, I am not totally against them associating with each other.

***Tip: You can also try a Trifiold flyer if you want to test a mailer that is really unique as well. 2.