BRRR Investors, I have a question about loans...

Hello everyone! I'm excited to announce that I am buying my FIRST property as a real estate investor. My wife and I are excited about this opportunity; with that said, I need your wisdom.

ABOUT THE DEAL...

The house is worth around 140k. We are doing seller financing for 60k of the cost. This means I need to acquire $80k for the rest of the house. I plan on BRRRing and putting 15k in rehab and hope it ARV's for around 160k (I plan on hiring an appraiser). I do have 20k in cash as well that I could use for a downpayment.

QUESTING ABOUT THE FINANCING...

What type of loan should I use, AND how would you go about it if you were me? Since I am 'technically' buying it for 80k even though it is work 140k, can't I get a better loan since I am only taking out 57% (80k/140k) or even WITH rehab it would be 71% (100k/140k)? Am I missing something?