I recommend you go visit a few times to network with local investors or find an investor friendly agent so you can gain local market knowledge, find off market deals and for things such as showings, picture taking or getting accurate comps.

No Capital gains tax if I sell one day either. 

.: I would go HELOC for sure that would be best as others were saying the lower cost for the money changes between paying a higher rate for a personal line and typically personal lines they want a higher monthly charge as well independent from the interest rate.  

But if your goal is to leave your day job soon, multi family will offer more cash flow typically.

I don't know the rules in the US, but in Canada, you can do that every 2 years and when you sell, you don't pay taxes on the capital gains.

You didn’t mention the property or deal specifics, but for many deals in the recent years, there have been amazing and unusual gains due to multiple unnatural circumstances.

@Emily Gowen so as you pointed out you would not have to do a 1031 exchange on your current home to avoid the capital gains tax and coupled with what Dave Foster pointed out I think, speaking from experience you would have a high likelihood of success. 

The high end is the 20 or so co ops on 5th Avenue or Park Ave (one is on East End Avenue) that require liquid assets of $100 million + to gain board approval.  

@Kaleb JohnsonRecommend you first figure out the property Class you want to invest in, THEN figure out the corresponding location to invest in.Property Class will typically dictate the Class of tenant you get, which greatly IMPACTS rental income stability and property maintenance/damage by tenants.If you apply Class A assumptions to a Class B or C purchase, your expectations won’t be met and it may be a financial disaster.If you buy/renovate a property in Class D area to Class A standards, what quality of tenant will you get?

And touching with owners pitching ways I can gain control, to then monetize.