@Cole U. I am probably from a little bit more of a conservative school of thought when it comes to real estate investing. I fully understand leveraging and the multitude of other factors that go into real estate investing and creating an ability to scale, but I also do not like the thought of emptying the back account to try and acquire a property. I prefer to keep a healthy savings to prevent those "crisis" moments from ever occurring, and I really like dealing with OPM (other people's money).
If this were for a potential flip and things looked incredibly good, I would be slightly more inclined to purchase with a little bit less of an emergency fund as you would be creating a quick turnover and could replenish the savings (hopefully). With renting, your income will likely be a slow build back into your savings and you have to consider all of the potential pitfalls of renting, i.e. renter turnover, vacancy rates, market fluctuations, repairs, and so and so forth. I absolutely do not want to discourage you from investing as I feel that it is likely THE most incredible source of wealth building, but you need to know the ins and outs as much as possible to keep from losing your shirt on a deal (or being caught with no money in the bank in the event something unfortunate comes up for you or your family).
As for HELOC, I don't really have any experience with this, but I generally stay away from things that pull my personal assets under the gun should a deal go bad. Real estate investing is a business without a doubt. With that being said, if you run the numbers and it makes sense (and you are comfortable with your risk), feel free to pull the trigger.
As for other programs out there, sometimes you have to consider options that aren't as advertised. Most lenders will require the "live in the home for one year" in order to qualify for their programs, but there are some instances where you can develop a relationship with a local back, show them the numbers if they are rock solid, and try to work a deal. I haven't tried this approach yet as my first home was a primary residence before converting to a rental, but I have spent time cultivating a relationship with local lenders (and investors) for when I am ready for my next deal.
Last word of advice (and I apologize for the lengthy rant) but probably the most important thing I have learned about real estate investing is to be a "transaction engineer". Make sure you nail your numbers and have a couple of exit strategies. Buying with only one exit option is dangerous in any deal.