I know a few people who have shown interest in funding some of my future deals and I was wondering what was the best way to approach this from a legal/tax standpoint. Ultimately, I know I'll need to talk to an attorney, but I wanted to get a general idea first and do more reading on it. 

I have two scenarios I want to address:

1) They fund 100% of the deal as a loan. 

and

2) They want me to manage their money and invest it for them in real estate.

What vehicle would I use to have them transfer me the money, without incurring taxes? I don't want the IRS to think that I am getting "free" money as gifts, laundering money, or anything of that sort. 

Am I allowed to just have them wire me the money to a separate bank account (intended exclusively for funding deals like this) or is it better to create an LLC with a new bank account? If an LLC was required, would I be allowed to run both scenarios under the same LLC?

Is there any particular documentation required for either scenario?

I may be completely off base, so let me know if there are other ways to run this. Thanks!