Rookie looking for advice

[Scott Davidson]

I've been presented with an offer in the panhandle of Florida and weighing my options.  

I found an off market house that would go for over $600K if it hits the market.  I have negotiated terms for owner financing to be $565K with 10% down, and two options for the terms are...

20 years at 5% for a payment of $3356/month

15 years at 4.5% for a payment of $3890/month

I would also need to cover the insurance and HOA ($1400/year or $117/month)

I have a rental that I make about $500/month in another state and I have a good amount of equity in that property. I have a HELOC on this property that I will use for the down payment. If needed, I could sell this property and easily pay down and reduce payments on the new property but I would prefer to keep both.

Through a friend, I already have 3 families interested in renting the new house for $3200/month.

I know this deal ultimately puts me in the red as far as monthly payments, but I'm looking at all options to make this work.  The house is surrounded by $1M+ houses and the area/market continues to grow.  

Does anyone with more experience have ideas on how to make the numbers work a little better?  Or am I just chasing this too much?