I looked them up and their address is in Minnesota, but also were incorporated in numerous other states.

Your client should look at incorporating some substitution rights in the lease which gives them the opportunity to switch the leases to another property.

I only responded asking for their company name, contact details/website, and which state they are incorporated in. 

Ideally, i'd like one piece of software or cloud based program to handle it all.I want to start off as efficiently as possible in hopes that when I have more properties these platforms (or hopefully one platform) are easily scalable to incorporate new acquisitions.My initial thought was to purchase quickbooks and figure it out with one property since there seems to be a learning curve (my accountant highly recommends quickbooks).For the property management, Cozy.co seems to be a cost effective way to go but is it better to go with Buildium (which has bookkeeping too) since the cost scales accordingly?

Account Closed why limit yourself to one "route" take what works from a bunch of people and incorporate it into your own life.

Once the LOI is executed by both parties, then you hire an attorney to write the PSA (Purchase and Sale Agreement) and incorporate the terms of the LOI into it. 

I've started incorporating the properties I own.

He has now incorporated that statute into the counter claim the seller has filed.

You can still open a bank account from New Zealand it's just a bit involved.Also regarding LLC's make sure you incorporate in a state that makes what Americans call "piercing the veil", (looking through the LLC to the individual owners) difficult, does not have high sales and franchise taxes and has low annual operating costs to keep it legal. 

Just be sure to spend the time vetting the PMs and incorporate that into the numbers when evaluating a potential deal.