Subto/Seller financing advice

[Taylor Bettencourt]

Hello, 

I'm looking to purchase my first home (not an investment property initially) with either of these types of financing. I believe Subto is technically the way I need to proceed due to the home having an existing mortagage. It is an off market deal that needs work to be comfortably habitable and I'm trying to think of how to structure the offer. I would like to request a low interest rate from them as well as a purchase price around $180k if they would take it. Ideally this would be amortized over 20 years or so. Has anyone had any success with these types of financing?

Thanks!