As long as you have a plan to pay that HELOC off quickly that is the key. 

I would say that it is generally better to work with multiple brokers than single sourcing.

Expect them to try to play if your feelings as well, so pack them away and put under lock and key.

What investing methods (buy & hold, turn-key, BRRR, flipping, etc)?

I think I would settle for $100-$150 if it was the right deal cause atleast you are starting your portfolio and building equity as time goes on, but still, availability is key and just not seeing it.

MLS is the only source of properties for me so far.

Money is the key plain and simple.  

Don’t use online resources as a primary source of data to base your decision making on when investing in RE.

Turn key properties just don't pencil out as good fit investments for me.

Any recommendation would be great, like a website or any source.