At the same time, though, it's all built on a house of cards/credit.  

If the deal is good even with borrowing the funds, then go for it.Refinance your house.Home equity line on your house.Sell something expensive (even your house if the deal is good enough)Put it on the Credit Card (works wonders, IF you're sure of your numbers:)Call everyone in your phone contacts and tell them you have a $50,000 opportunity you'd like to tell them about.Ask everyone in your contacts who they would be talking to if they had a $50,000 opportunity.Put a post on facebook or your social sphere of choice that you have a $50,000 opportunity for the right person.Call several local Realtors, specifically ones that do investments and commercial and ask hem if they're interested in a $50,000 opportunity and ask them who might be.Borrow against other investments like stock or borrow from your 401kBorrow from another investors 401k, your Mom's, your neighbors. 

Now that some of the cards are falling into place to invest in our first BRRRR here in the Houston Area, I've thought about approaching him for funds once I get everything lined up. 2 part question: What is a good interest rate to approach him with, and what is the best means to make this happen to protect both parties?

The downside is tenants have to pay online whether it's through ACH or credit/debit card; no money orders or cash.If you let the tenants pay by cash make sure you are protecting yourself. 

Have business cards that say you buy houses & plexes.

Who knows, complete wild card.

@Manuel Alexander i actually had a family member of mines turn me on & but most i spent so far is about 100 bucks on badit signs & business cards

Be sure your debt ( credit cards, auto loans, store card ) are 40 % or less. 3 0% would be even better.

I've also been reading Chad Carson's Retire Early With Real Estate and am fascinated by the concepts and stories of other real estate investors.At the beginning of 2016 I took control of my finances and aggressively paid my way out of $25k worth of credit card and student loan debt (huge "thank you" to the Personal Finance subreddit for being a fantastic resource).

The variable loan is linked to an offset account and my expenses are funded via credit cards.