HELOC vs Cash-out Refi for Rental Property?

[Jack Chase]

Hello all, I'm looking to pick up a rental property and am weighing the options between using a HELOC or a cash-out refinance of my primary residence and looking for experienced opinions.

I just did a cash-out refi in April and locked in a 3% rate but still have ~$200k in equity. I'm now looking to pick up a rental property for about $80k and would prefer not to cash out investments or use savings to make a down payment. Current HELOC rates for my lender are "Prime -.25%", which is currently 3%, and is variable. The obvious benefits are that it's faster than a refi and is only a fraction of the closing cost. And the downside, of course, is that the rate is variable.

If I were to do another cash-out refi, I could lock in a 2.75% rate for 30 years, but would be subject to ~$5,200 in closing costs and would take longer to process. 

What would you do?