Is the practice that the banks and hedge funds use open to LLC's, partnerships, sole proprietors,etc?

You could set up the JV with an entity like a LLC or a personal property trust. 

What I can't figure out is why would an agent act this way toward a person (or small LLC in my case) who is willing to purchase a home they bring for cash, and realist for them to double dip.

2) Is there a way we can shape this LLC to be flexible towards other investments?

Getting my LLC set, and particularly getting financials in order took longer than I wanted, but it has been constant progression. 

First would a lender fund a new LLC if they put 70 to 80% down?

Must have an LLC, ITIN, etc.Some of my Oz relatives have invested in the U.s.

Think outside the box.Put the 2 rental properties (you want) into a company and call them a "ABC Business LLC"Leave the 3rd in your name.Sell the 3rd property for what you paid or for a slight loss  so you don't yield a profit.

If I can present these potential investors with a legitimate wholesaling opportunity, having transparently quantified my due diligence on the property, I believe that this could be my way to break into the REI world.After reading many forums on setting up the business side of REI, I think having a Parent/Subsidiary structure will be most beneficial, as not only will I have personal asset protection, but also because LLC's are cheap and easy to set up in Michigan. 

So far we have been able to wholesale 4 properties and acquire 2 rentals in the 8 months R and R Homes LLC has been in business.