If landlording has become a chore for them they might be willing to do a deal with you that is favorable for all parties.

This is not the same process as a SFR purchase, where the buyer obtains a letter of qualification from a dubious mortgage broker; this is a very intensive evaluation.That being said, nothing is to stop any interested party, qualified or not from making an unsolicited offer.  

And the Professional Investors Guild is a great resource for learning about wholesaling and rehabbing, and of course networking. 

The most useful resource for me is looking at other professionally done houses.  

If you own the land outright you will be able to negotiate with parties your interested with working with.

So my question is geared to the real estate professionals and I'm interested in finding out, what is the best way to find an agent that will help me find a beach rental property while being considerate of their time knowing this process could take months?

. - little tip: you can look for ran down properties at the same time.Talk to any real estate professional you can!

Otherwise, go above board and find a good, professional management company to run things. 

Neighborhood demographic: will you be renting to students around a university (generally higher rents but more turnover), young professionals, or families?

@Eric Hansen However, a big part is how do your fiance feel about real estate investing?