While we won't give up, I am wanting to explore the option of purchasing land to build multiple glamp sites, small structures and eventually a small site built home (I know this can take TIME). 

I also realize that our business is one of reputation so being diplomatic and asking nicely and respectfully goes a long way when I am trying to do things for my clients that might be considered an inconvenience to sellers or other agents.Communication is also a huge part of a good agent’s tool belt.

What are some options I can explore? 

Exploring all options at this point.

My primary plan was to do a HELOC after closing to tap the equity, but I'm a little concerned rates will rise significantly so I thought I'd explore this as an option. 

Haul in dirt from reputable source.  

Your friend is concerned for you that backing out may hurt your reputation. 

Once you have that you can bring it to an active and reputable investor or wholesaler and they can help you figure out if it's a deal; and if it's a deal they would work through the transaction with you.

Looking for some recommendations for a reputable impact window company around the Broward county area. 

I’m looping in a friend and associate @Dave Foster to help you understand the Dos and Don’ts when exploring a 1031 and the guidelines.