For extra formality, put it on a nice document with your letterhead.Re: Non-Binding Letter of Intent to Purchase Real Property Located at [Property Address]Dear [Recipient's Name]:This non-binding Letter of Intent ("LOI") is submitted by [Your Name] (the "Buyer") to [Recipient's Name] (the "Seller") with the intention of setting forth certain preliminary terms and conditions for the proposed acquisition of the real property located at [Property Address], inclusive of all improvements, appurtenances, and fixtures thereon (the "Property").Purchase PriceThe Buyer hereby proposes to purchase the Property for a total consideration of $[Amount] (the "Purchase Price"), which shall be subject to adjustment based on the results of the due diligence investigations and final negotiations.Earnest Money DepositContingent upon the execution of a definitive Purchase and Sale Agreement (the "PSA"), the Buyer shall deposit earnest money in the amount of $[Amount] (the "Earnest Money") into an escrow account designated by the mutual agreement of the parties.

I have a seller finance/subject to calculator that I am happy to share with you via email.

I say soft because it is subject to change once you order the appraisal and move forward with the UW process.

After a brief search, the IRS says-For tax years 2018 through 2025, if home equity loans or lines of credit secured by your main home or second home are used to buy, build, or substantially improve the residence, interest you pay on the borrowed funds is classified as home acquisition debt and may be deductible, subject to certain dollar limitations.

You could sell it on a seller finance/ Subject to transaction.

Sean Terry focuses on wholesaling and subject-to from private sellers.

I am happy to brainstorm on this subject, any more thoughts?  

If so, they could change ownership of LLC to you and add you as authorized to get mortgage info.You would buy it subject to the existing mortgage.

Something to look into for sure if that's a route you are considering and have a primary mortgage on the subject property. 

You might try wholesaling, but even that is not going to be fast - find a wholesaler, go work for him for free for a couple months, soak all the knowledge you can meanwhile and read all the material you can get from internet, BP, Amazon books on the subject.