Hello,I am an entrepreneur having issues qualifying for a conventional loan.

Their credit score is also slight less than the minimum credit score required to qualify so I can reject them based on those grounds. 

This means that the two of you bought/own a membership interest (partnership interest) in an entity and did not buy/own real estate, so it does not qualify for 1031 Exchange treatment.  

Who can/should I use as a qualified intermediary? 

There is a fairly new 20% pass through deduction you may qualify for that could help you, but not everyone qualifies.

@Erik Estrada right now Amex got me at a special rate of 9.99% I’m talking to my lender right now on qualifying to get a loan to buy the property

I highly recommend a well-qualified REALTOR who works with investors and knows how to help you best.7.

Deegan and @Arda Bircan There are technically 7 Tests for Material Participation (but 3 that are most common) -> the individual 500 hour mark, that the activity of the individual is substantially all, and that the individual participates more than 100 hours + no-one else spends more time than them.Litmus Test: Are your hours integral to the operationsThe hours that qualify must be substantially all hours and have a legitimate impact on the rental activities.Activities that generally count: showing the property for rent, taking tenant applications & screening tenants, preparing & negotiating leases, cleaning & preparing the units for rent, repairs, and improvements, managing the construction, purchasing supplies & materials, inspecting the property, responding to tenant complaints & inquiries, collecting & depositing rents, evicting tenants, writing & placing advertisements, and working on your websiteActivities that don't count: education & research, investor-type activities, and travel time..

It looks like I “may” still qualify for a partial exemption based on those 18 months. 

Type doesn't matter.What gets people confused sometimes are the terms "like kind" and "qualified use".