I thought about using it for only the 20% down, but it seems I'd get more leverage/flexibility if I just paid cash outright, then had a great asset to borrow against! 

I have a strong relationship with a regional bank that provides me lines of credit as well as flexible loans where my interest is generally prime +1% or prime +2% depending how I structure it.  

Credit unions have their own funds not Freddy's so they can be somewhat flexible and make their own policies like the deals above. 

The key for us with our business plan was flexibility.

Sometime you have to be both flexible and courageous when it come to investing.  

I generally like to use the most popular, flexible, free themes available.

They seem to be more flexible with the down payments & require it based on the appraised value not on the purchase price, unlike residential lenders. 

The previous owners were too flexible so we are trying to ease in to educating the tenants that they need to be closer to on time. 

You might try talking to a local bank that holds their own mortgages as some of them have different requirements than the big banks and might be more flexible.

So stick with your business strategy but be flexible to the change in markets.