Hi @Justin Schrey, welcome to the community!
Your goal is certainly attainable. All the success stories on this site are proof!
I would advise against using a HELOC to buy a property. The last time inflation was this high, mortgage rates were 15%+ so if you are not planning to pay off the HELOC in a couple of years, I would utilize a different strategy.
There are a few good options but neither myself nor anyone else will be able to properly advise you without knowing more about your current mortgage.
If you are accessing some of the equity in your primary residence, you can put more down on a nicer property.
The $100k property cashflows well now but if it becomes a crime scene or your tenants stop paying rent, you could lose all of that.
As long as you have a good property manager in place, you should not have too much trouble with vacancy.
You must also be aware that good property managers do not want to deal with headache properties so to get the best, you must have a property in at least a C-class neighborhood.
Additionally, the SFH in a nicer area will experience more rental appreciation as well as more price appreciation.
If you really want to speed up your timeline, you could buy 5-6 homes in the $150k range in a decent area with $30k down. They will likely be cashflow positive and you can offset the higher mortgage payment on your principal with the cashflow from those properties.
Within a few years, you will be cashflowing a couple thousand dollars a month and by year 8, you should be making $3-4k per month in cashflow and have hundreds of thousands of dollars in equity.
The good news is that you have options.
Hope this helps! Let me know if I can be of any assistance.