My credit and cash flow situation is pretty good but I am thinking of worst case scenarios. 

The borrower and the asset itself.Borrower:Your credit (are you a trustworthy borrower), are you capitalized enough to float this project/ cover the debt, track record (borrower/ contractors experience).Asset:Comps (as-is & ARV), LTV metrics (lender can help verify these if you have questions), detailed budget and scope of work, tentative schedule, exit strategy.Of course any lender/ partner will dive in a little deeper after the initial pitch but if you have all of the above ready for your initial conversation it will go a long way in getting deals approved/ partners on board.

Taylor Cochran keep in mind that if you are going to have a bunch of equity in the house after you purchase you could possibly tap some of that equity through a Home Equity Line of Credit.

The problem is that i have a poor credit score.

I have been told people are 4.5% at certain credit unions but have not found that.

There are a lot of third party services that will do credit and background checks for you.

to pay off my credit cards and use the rest for down payment for a quadplex !

why not do like i did, go down to local Credit union and start it up?

All that assuming you can get a loan from a bank (maybe someone with bad credit).

Before you purchase a property, I would suggest going to your bank and applying for an increase in your credit card and line of credit limits (don't use them, just have more space available).