I am leaning towards conventional since I do not want to pay for mortgage insurance, but this involves a significant chunk of cash up-front.I still have a lot of details to work out right now, but I guess big picture that is my goal. 

I've been leaning towards the FHA 3.5% down and that's not something we see eye-to-eye on.

We have access to a $250,000 HELOC and $65,000 cash on hand we are willing to invest.I have owned two residential rentals in the past and have managed them both myself, I am at a point in my life where I do not want to do that again.Our first deal together will be her first deal.We have both been studying real estate investing all year long and plan on pushing for our first deal as of January next year so our finances will be aligned.I am leaning more towards a quad plex minimum or to even attempt to push into commercial size rentals instead or even try and find a small strip mall since I've read multiple places that commercial is a lot more beneficial and it's easier to manage businesses rather than tenants (but with the right property management I suppose neither of those points matter)She would rather start smaller, still multifamily but a duplex or triplex max due to simplicity and to get our feet wet first.

I was leaning towards the HELOC bc of the lower payment and paying the mortgage off faster, but I really want to find a 10+ unit to get into multifamily, so the cash in hand might be a better option.

My father passing on sort of had me leaning towards selling. 

I have no experience, this is my first investment, so I am leaning towards a house hack (2 or 3 unit building) living in 1 unit, rent out the others and if my monthly outflow is less than I pay now in rent, then I am winning. 

It’s also way more convenient to have a 8-12” cabinet/counter there too for cooking.

Was it their under convenience, has there been a boundary line agreement?

So I would keep earning and banking and start leaning more and more about house hacking which will likely be your best first endeavor.

Pro and con list below (as I see it).Flip Pros: Major market home shortage - would sell instantly, Should be able to make a good profit, Fairly quick moneyFlip Cons: I hate dealing with contractors, a few months of construction, not a long term wealth strategy, I hate dealing with contractorsFix and Rent Pros: Equity, long term wealth, good rental market, one of few 4 beds in the area, great hipster neighborhoodFix and Rent Cons: I hate dealing with contractors, I've never been a landlord and am nervous about it, it's not convenient to where I live.