looking for down payment funds: Cash, HML, Roth , or HELOC

[Micah Mcarthur]

I am starting down the path to REI, and I am trying to understand my options for acquiring the capital to invest with. I do not yet have a property selected, but lets say I want to use the BRRRR method for a SFR with an ARV of $150K. I need a down payment, and I need funds for the rehab. I have the following options

Currently, I only have about 10K on hand, but I could bump that cash on hand up to about 20K in the next 4 month.   I could get the down payment, but strap myself for cash, and still need rehab money.

I have about $30K in Roth contributions that I could withdraw free and clear 

HML--- I dont know too much about this yet, my wife asked if Hard money and private money had anything to do with the mafia....

Or......

Could I use a HELOC, for everything?? ...My residence is worth about $250K, and I only owe $100K, so I could use the $150K equity to invest in a property, then refinance, and pull my capital back out and pay off the HELOC?

this seems too easy.  what am I missing?  My wife and I are both a little nervous about chaining our house to some investment properties.