And I've had good experiences using referrals from the plumbing and tile suppliers.  

I would recommend doing extensive due diligence regarding, referrals, recommendations, connecting with people directly who have purchased out of state, and spending a lot of time on the phone calling providers/property managers and asking a LOT of questions.

Experience, third party referral from actual clients and colleagues, timely responsiveness, ability to play well with others (your other professionals) is critical, lastly price (there's some difference but the range isn't that great).4.  

In fact, my realtor has given me referrals for properties that he knows won't sell quickly on the MLS.

I feel this is a great way to be successful in the REI industry & be influential in changing mindsets by using financial wealth to promote the importance of education.

I would suggest reaching out to your network, make sure everyone you know, knows you buy houses and that you'll pay them a referral fee if they bring you something good.

It was referral through a realtor I knew. 

Investing turn key out of state is no picnic, and certainly not as easy as promoters would like you to believe.

I have a graph of these on an article on my site, but since Bigger Pockets does not allow self-promotion I cannot link to it.

You can get referrals for these people right here on Bigger Pockets.