Cash out Refi vs HELOC?

[Brandon Knight]

Hello! I have a two-part question if anyone has any tips or tricks that would be greatly appreciated!

First question: 

I am trying to figure out how to grow my "snowball" as a real estate investor. I currently own two rental properties. I am trying to figure out the best way to get more funds for the next homes. I have approximately $150,000 in equity in one of my homes and do not know if it is more beneficial to cash-out refinance or to get a home equity line of credit on the home to apply to more properties. I am hesitant to refinance because I have a 2.6% interest rate on the home but at the same time the HELOC is a variable rate. Anyone been faced with this same cross road or have any tips on what might be the better option?

Second question:

What is a good cash-on-cash return on a single family rental home that seasoned investors try and aim for? Do you aim slightly higher to give yourself a little extra safety cushion? 

Thank you for any responses, it is a ton of help!

Brandon