House hack with additional funding from parents, credit cards, etc. 

I liked that it was all online, competitive and a big discount for getting a Costco card...

If possible get your partner to raise their credit score, they don't have to raise it by that much, if they have credit card debt that is a better investment for them anyway. 

Our primary house is a fixer upper that I have been fixing little by little myself and over time that run into 25k credit card debt.

Fortunately for us, green card holders, foreigners married to US citizens and more are not defined by the IRS as non resident aliens. 

What I am trying to do is create some cards maybe the size of a postcard that I could hand out with information on how my company can benefit my target audience.

Take a notepad and business cards. 

I obviously don't want the card to say "Dear Loomis Plantation Estates LLC, I am interested in buying your property at (address)." 

I was advised just as you advised me James to either open up a credit card for the necessary amount to get the down payment, seller financing, private lender or sell my rental house and use that equity to buy the next.

In other words, you can always offer more, but it's much tougher to offer less once you've shown your cards and offered too much!