My plan is to fully rent out the house I have and house hack the next property while still investing in real estate through other avenues.

You're perfectly capable of throwing some aggressive bids that make you comfortable entering and as you see one that fits, maybe up the ante for one that fits all your criteria but right now you can operate with no pressure regarding that. 

We own a primary residence and plan to stay here (house hacking is not for us), and have been saving scrupulously for the down payment of our first investment property, ideally a 2-4 unit multifamily. 

My game plan is to do a house hack as I have very little capital.

Yes you need a RE niche firm but tax prep without proactive year round tax planning is not very valuable.

I have built around  20 homes in the past 2 years all with the exact home plan and  I been doing spec and custom homes my entire life.

There's a number of people that teach/coach how to start and run a STR company...Tony and Sara RobinsonMicheal Sjogren Rob AbasoloMicheal ElefanteAnd others depending on what fits your goals. 

I am planning to do a house hack on a property.

.- Location Focus: for multi-family in DFW, as the supply is low you will need to look what fits the best for you.

I definitely planned on being upfront and maybe even offering discounts.