VA or FHA allow smaller down payments.  

My problem is I don't have 15-20% for the down payment, and I'm not sure I will be able to get the 5% down conventional loan because I won't be moving into the property within 60 days.

We tried to resolve the issue with the office manager, but eventually had to stop payment. 

We have been reading books and doing research, but no boots on the ground yet, so we have no idea on the time frame.We will only have enough for a 5% down payment for a 150 unit by the end of the year.

The original lease would still stand, but you can have them sign an Addendum just to acknowledge the switch of ownership of the lease ( you) and where payments are to be sent and how they are to be made out, or if online payments, how to pay. you can not physically change the rent and i wouldn't bother re writing it on your co. letterhead, that would be a waste of time and a headache.

***Renting in the area is thriving because people are unwilling to pay market value for a house, unable to save for a down payment or uneducated on the minimal cost barrier of entry to home ownership.

This is my plan; I plan to receive a gift from my parent which I hope to use as a down payment for the property.

For example, there was a triplex that is out of my current monthly payment range; however, with the potential rental income, the mortgage payments will only be a few dollars over. 

Can you show a rent payment history for current Tenants/have they always paid on time?

If I didn't realize before that this was the expensive and slow way to go, I sure did after writing that down payment check.