Unless he's a RE Broker he can't PM for you after he sells, in Missouri you need your Broker license to PM a property that you don't own, unless you're an employee of the owner.

Sure, it can help if you're talking to people to mention that you are a broker, but outside of that, you don't get any special privileges or knowledge just from earning your RE license. 

Does anybody know what is the best way to get in touch with local multi family broker?

Real estate, especially multifamily, is a team sport and you won't be able to do this alone.Attend a local Meetup group, meet brokers, meet local investors, and provide value in anyway possible.

@Kris BensonWould I look this information up myself or should I ask their listing broker for the information?

Run your offers by the listing broker before you submit them.

There are work arounds especially if you have broker dealers involved but you end up running out of people you know pretty quickly. 506(c) allows general solicitation but only accredited investors are allowed to invest and they have to provide evidence.

I would have similar reservations working with an out of state mortgage broker. 

@Kyle Ferguson If financing is your issue, network with a successful mortgage broker who can is knowledgeable about the various products available to you in your area.

Did find something reasonable through a broker.