I'd talk to Dale Carlton maybe, he is the exclusive listing broker/agent of one of the biggest residential investors in the area so he will likely be able to work with you or point you in the right direction.

I am from NJ, and up there they have an "exclusive realtor contract" which realtors would ask clients to sign.

It's like they want it to be inconvenient so you will use them exclusively but honestly it just makes me want to use it less. 

I delivered newspapers as a kid and even delivered pizzas there not long ago. 

There are no exceptions for a certain arbitrary number of employees or net worth, nor is there a “small business” exclusion or exception for businesses with fewer than five employees, or for businesses that satisfy some other arbitrary size, net worth or similar criteria.

How does a wholesaler market the property they just contracted for; list with an agent, run ads to find an assignee, Craig's List, newspapers, signs, open houses?

Because you rented out you no longer get the $250K capital gains exclusion for primary residence but you get the 1031 tax deferral.  

Even some who do it exclusively.

Riding on his coattail, I was able to attend exclusive meetings and lunches for wealthy individuals, who have liquid assets >$5MM.

I'm reading a book and the author mentions the primary residence capital gains exclusion.