interview a few and let them see past returns and tell them your plans and goals and it is usually an easy decision to pick one. 

You can interview property managers any day and see if you get the warm and fuzzy on them.

I'd reach out and interview several buyers  agents and see who has a track record of bringing great opportunities to their clients.

Even without having the highest offer.In most large multifamily transactions, the seller and broker will hold a round of interview calls with the top 3 to 4 buyers. 

Definitely make sure he's one of the lenders you interview and consider.

(source: Deloitte - Blockchain in Commercial Real Estate).David Sacks, former COO @ Paypal, gave an interview to Fortune magazine recently, where he predicted that real estate will be the vanguard for a market where all sorts of assets, from fine art to shares in private funds, will be tokenized on a distributed ledger”.

As far as the investor friendly brokerages, just interview them when you go check out offices.

Meet with a bunch to interview them.

I would speak with a couple of different local real estate agents, let them know you're interviewing a few of them, and have them give you a range of the value.

Put ads on upwork and PH jobs then interview anyone who submits and completes these criteria.