Despite what appears to be a bargain, you should realize that that is not a great neighborhood and, although houses built in the 1890s are totally cool, they typically need massive work to rehab....lathe and plaster walls, fuse boxes, exposed wiring, non-standard construction, etc.

Then, with the "massive wealth" gained, then plough it into cash flow with which to retire (or any other investments). 

I am not looking to grow a massive real estate portfolio which is why I am comfortable saving with my full time job and using this cash to purchase more real estate. 

If so, why not house hack one (saving on the massive down payment, having to pay refinance costs [or] HELOC fees, etc.), put 25% down on the other property and keep the rest in the bank for reserves?

took out the massive wood stove and am adding a nice split system for heat and ac.  

In my opinion it's probably best starting off with the small deal and working up. you don't want to get caught with a disaster on your hands on that massive property without the financial ability to pull yourself you.

Houston might be more attractive if you think of Warren Buffet value investing approach.

Takes a little longer to close and can be harder to get a seller to accept it when you have competition, but to you the borrower, not having PMI with 0% down is a simply massive boon for you and your cashflow. 

I need to find out what the massive multi-family property managers use...

@Caleb Rigby Warren Buffet has 3 rules which all reiterate don't lose money, however, they weren't major losses.