FSBO duplex - HOW DO I GET IN??

[Chris Jackson]

Hello BP world! So I am new to investing. I have gone through a lot of training with the Rich Dad program and I have a mentor in my corner who is very experienced; however, I wanted to start reaching out here to you guys also so I can make MORE CONNECTIONS. 

I am going to give my semi-quick story now.  If you don't care, just skip the next paragraph and read my preliminary analysis of the deal that I need help on.

This morning I was searching Duplex FSBO's on Zillow and I found one in Chambersburg that I liked, so I called up the owner. The owner told me that he had already sold that duplex (BOOO!) but he had another he wanted to sell soon anyway (YAAAY!). So he told me the information and I am going to go take a look at it after I get off work to see what I think. Here are the stats:

S/S 3/1 (each unit) Duplex in downtown Chambersburg.

Owner has long-term tenants in place who pay $750/mo each ($1500 total/mo.)
Owner has existing mortgage of $90K that he would like paid-off, but isn't desperate, so he's not going to just settle for an offer of $90K. He IS willing to do owner-financing, but it sounds like he much prefers to get his mortgage paid off on this property first versus owner-finance the entire purchase.

What is the best way to get in to this property and make us both happy?  I want as little (or no) traditional financing as possible and I do NOT just have $90K sitting around in the bank (new investor, here). I am hoping for maybe two or three solutions I can provide this guy to make him happy - it sounds like he might have other properties he's going to want to off-load too soon.

What do you guys think????