Any ideas on creative financing

[Indra H.]

Hello fellow investors, im looking for your advise as this forum is full of experienced and creative real estate genius. my family composition has recently and suddenly changed, so I need to move to a different home. This will not be an investment property, this will be used as primary home. Three months ago I quit my job and started a private practice (mental health). Although my credit is excellent, I am a new business owner so im not able to secure conventional financing. Im in negotiations with an investor that is selling his house and is willing, with a substantial down payment, wait two years before I refinance the house and pay him the balance here are the numbers

360k sale price

144k down payment

216k balance (4% interest only due monthly or at time of refi in two years -- $17,280)

after two years refinance and pay him off. My fear is that in 2 years the house won't appraise at 360k and I would have to borrow more than the 60% that I owe him.  Seller is someone flexible as he owns the house free and clear, but thinks he is "too old to finance long term".

Any ideas how we can move forward?

Thank you in advance for your ideas