Thanks to excellent personal credit guarantees, I’ve been extended 2 lines of business credit cards.

This means you must wholesale the majority and keep a few others.If cashflow is not an issue then holding assets wins hands down. 

I have access to credit cards totaling over $20,000, but it occurs to me that getting a loan would be lower interest for a down payment.

Great win.

Additionally, setting up this first partnership meant ensuring that we have the infrastructure in place (credit cards/banking/operating agreement/business plan) to make sure we're ready to scale up from here!

I've been telling clients that owning in this market is winning, simple.

From there, get cards and contacts and start networking!

When looking at towns in West Palm, North Palm, Palm Beach Gardens, Jupiter and Tequesta, it seems that any house in decent condition is getting 4-5 offers. In addition, at least 1 is cash at or above list price. I am...

How did you win?

I'm glad you've learned some tweaks to make the next round of this even better, but don't minimize the "win" that this one was, both for you, the buyer, AND the seller you served with the cash offer!