But get more than one additional quote, because the cheapest is frequently not the best choice.  

Tough to get the timing right -- tough=impossible -- but you'd be looking at it as a very long term investment and not checking it daily.Real estate investing gives you tax benefits, the benefit of having a tangible asset (if you care about that), and a variety of other benefits.

Bigger Pockets frequently recommends using realtors as one of the funnels for investment leads.

Your question is one that frequently goes thru the mind of a commercial broker (especially during the good times ;). 

Tenants may say they desire an option to buy or even a "rent to own" but frequently won;t perform on their end or want to misunderstand their rent payment is somehow a downpayment for the property or should be credited in this way. 

I am in the area frequently as my kids attend school close by so I am flexible when we can meet."  

And how involved you want to be.Dallas is a strong market, it's also a big market in my opinion so there is plenty of variety. 

Now, in saying that, you can get creative in how you touch your database, but make sure you're touching them at least 4 times a month in a variety of ways.

I actually hadn't considered the frequent vacancies due to all the PCSing.

People can be very attached to the property and they are selling for a variety of reasons, they may don't want to sell at all, but they must.