Definitely a good idea to go for a MFH. 

I had a decent idea about the upfront costs so I'll likely pull from savings and or open a no-interest credit card to fund them. 

We do not know where our passions lie at this time but am looking for ways to invest and love the idea of house flipping and STR, but honestly so open and excited to learn about it all. 

@Julio Arias PabonBanks are very difficult now to get a HELOC on investment propertyI would call around to local banks but most have completely got rid of that line of business

Always be in control  (not controlling, there is a difference) in your business and how you do things. 

My business partner and I have been coming across off-market deals and have a flip opportunity in Gresham and a lot in SE Portland for a new build.

I have been very impressed by their business plan and professionalism.  

Any experiences or advice on this would be greatly appreciated.Small Business Loans: Has anyone successfully gotten a small business loan to fund a down payment?

I could be off here, but my understanding is that if you are already in the business, you have a precedent set and can depreciate furnishings as you scale your portfolio. 

If you are using the HELOC proceeds to acquire land for a property that will be business use in some manner (a rental), then that interest expense from the HELOC would be deductible against that business project.