A lot of people decide to bring/raise investor money to the table as a foot in the door, but I also think there is options to be more creative and do the same thing.

You should offer them the option to leave. 

If you do not feel good about it, deny the application based on the son's statement that he is going to live there, or for other disqualification reasons.

Based on my research, it just seems as if more jobs moving to TX and appreciation is likely to take place in some of those "smaller" cities outside of DFW. 

Based on your PP the difference you would get investing that 5% wouldnt add to more than the extra 3% of pp you get.

Or have ideas on creative lending options as two separate down payments may be too much for us.

Cash out refinances of existing properties might be a great option depending on how those parameters look within your portfolio.

I am a contractor overseas (Germany) and as a network engineer for the DOD i will be working at Military bases. 

Based on a brief look, monthly cashflows for STR/MTR are not significantly greater than LTR and to my slight disappointment, it's almost very much the same with LTR.

We’ve got a great network of investors and some solid knowledge on alternative financing that could help you out.If you’re looking for funding options or just want to brainstorm on acquisitions, let’s connect and see what we can make happen.