One other thing to consider is tax implications if you sell. 

I also want to make sure tax wise I have the best structure possible. 

As far as I know it's just the jump in property tax that comes into play.  

Hi Jacob - I have a network of partners from financing to tax strategy, REI coaching, etc...who can help answer a lot of these questions and get you some guidance. 

a single family to a multifamily property is perfectly fine.Lastly to your question - You must purchase at least as much replacement investment real esate as you sold if you want to defer all tax.  

@Josh Roman I have one that’s two houses with three units on one tax parcel linked to a second tax parcel that has always been on one mortgage.

Same school district, property taxes etc.

About $900 a month after taxes/insurance/and misc repairs. 

Since Florida has no income taxes...

He is ONLY willing to sell by owner financing.I am not a tax expert in estate taxes, but my guess from knowing others who have had similar situations is that IF he sold it outright for say 300K, he might have 75K of taxes.