Structuring a deal - What are my options?

[Philip L.]

Yesterday I agreed to purchase a house in Michigan sale price is $110,000

The seller is asking that I pay $40,000 upfront to eliminate the current mortgage then the remainder $70,000 on seller finance for four years 
can be longer as the seller likes the idea of a regular income.

The seller doesn't want any connection to the house and ideally wants to be just a lender. We talked about what else could be used as collateral and I suggested my business but I am not sure how to structure the deal.

I currently have an LLC that has:
1 rental with $80,000 equity  
$26,000 cash in the bank
+ if we do this deal a property valued around $110,000 

I'm thinking that I could draft a promissory note from the business that states the agreed terms 
Or should it be the seller owns a % of the business until the $70,000 is paid in full

Would love to know everyone's opinion of the best way forward.