Would need a gate as well and I am not confident in how to price it, so I am looking for contractors that would offer an honest price and do a good job.Also, anyone have a good ballparking method for cost of these things?  

As I understand it, a landlord is required to keep tenants' security deposits in a separate escrow account.  

Make sure the seller transfers the security deposit to you at closing. 

There is also more security with a multi family as you can have a vacancy and still be positive.

@Austin Fruechting : If you ask Bill Belichick what's the best play, so long as he's off-record, I'm sure he'd reply "Whichever one was developed through my use of spies and other cheat methods" :D

Assuming you collected security deposit for down but tenant hasn't moved in?

Some people can't sleep if their money is at risk in securities.  

Even if the teacher had explored laws, one would think they would simply not offer the class to those in states in which the methods are illegal, but then again the teacher would be at least $5400 poorer.

Be sure to get the security deposits for all four tenants at closing.

The person leasing does not have to occupy the property but the lease has to  be executed - meaning signed by all parties and the security deposit already deposited into your account.  4.