Are the receipts and invoices that I will use for my accountant going to suffice for this?

They are asking if an ITIN will suffice in place of a SSN?

@Thomas SmithThere are several considerations that can go into the analysis of whether you need an LLC or whether a large insurance policy will suffice.

I think the BP calculator does a pretty suffice job with what you need to see in order to make a decision about properties.  

@David RipplingerThere are several considerations that can go into the analysis of whether you need an LLC or whether a large insurance policy will suffice.

Suffice it to say, all came to a screeching halt with c19. 

Although there's an argument to be made that getting adequate insurance should suffice, there's definitely an added benefit to protecting you personally should anyone be injured during the renovation of the property or as it's occupied as a rental.

Vacancy alone - 1 month a year should suffice.

Whatever you find, run it by your own attorney.To answer your question, there are standard real estate contracts that you can use (though you'll probably need to modify them), and there are much simpler contracts that suffice for private sales, which is what you're doing.

You'll probably need an agent when you get ready to buy but while you're just browsing this should suffice.