Any recommendations for good investor friendly agents I can shop the rate with? 

Hey John, As others noted, you might want to shop a few local CUs to finance this with a HELOC.

.- Shop around for lenders that specialize in owner-occupied multifamily properties.- Use tools like the BiggerPockets mortgage calculators to see how different interest rates and loan terms affect your cash flow.If you have more questions or need further guidance, feel free to ask Good luck with your duplex venture

My brother-in-law would gift his interest in the property to my wife (and we would fund him with an agreed upon gift in return) and then my wife would assign her beneficial interest in the land trust to the LLC owned by her as a single member.

You are looking to create the biggest spread possible so shopping around for the best rate and terms should be a priority.

@Megan Paquet NelsonA good remindee why investors really need to stop price shopping on insurance and really shop based on coverage, a great agent, and actually read their policies so they know what their coverage is and isnt.

You chose a property manager without shopping around and comparing multiple professionals in the market.

HI @Jyotin GautamShort answer is no in Texas Long answer according to the Texas Real Estate Commission " Under the amended rule, a broker could give an unlicensed person a gift of merchandise having a value of no more than $50 and this would not subject the unlicensed recipient to a charge of unauthorized practice as a broker, nor result in a violation of TREC rules by the broker giving the nominal gift."

This will narrow your shopping area then you can hunt for the deals. 

As realtor/investor who specializes in working with investors, I can be your one-stop shop here connecting you with home inspectors, general contractors, and property managers all of whom I know and trust.