I would focus on systemizing property management as much as possible so adding more units becomes easier over time.If your goal is to buy one property a year, then stick to your pace.

Supplimentally, Do you all reccomend any bank accounts where you can easily manage sub accounts within main account?

Do they use pen and paper to record this information or do they have some sort of software to manage it? 

There are more factors than just the community (#beds, level of theming, location to the amenities, style of home (single family, townhome, condo) and others) But I would strongly advise to stay within some of the same communities you mentioned like Storey Lake, Windsor Hills, Championsgate and a few others if cash flow is your goal.

Expecting big cash flow in multifamily apartments right now is kind of a fool's errand because if you find it it's probably in an area that won't be kind for out of state ppl with a third party property manager. 

If for aging population he might do ranch versus multi level.  

It would also be much easier to manage considering you are currently living in Arlington.

You have tax benefits through depreciation and you are gaining experience via property management.  

But I know it would make a good MTR, and managing it from next door would be easy peasy.  

It's best to have a property manager involved because they usually know the rules etc.