@Arthur L. Timmins Jr.
Who is your present home loan through? Whoever that is will probably be easiest to work with for the HELOC (typically) rather than another bank.
I might differ from the others, however I'd think a HELOC would be the way to go - little fees, and this allows you to use your house as an ATM if you need to act quickly (use cash) to purchase a property, then later if you are holding the property you can go back and get more permanent financing.
If you do a cash out refi on your house, you've probably just increased your house payment again and are locking yourself into mortgage payments again for however long your new mortgage is, plus all of the fees/taxes (mortgage registration tax, loan recording fees, fee for this, fee for that etc)
Maybe I'm a bit more conservative - but probably would make your life a bit easier if you have your house paid off and you are able to throw more of your cash into your RE business later on. Just another angle to think of.
There are also ways and banks you could go through where you'd probably have little money out of your pocket using a combo of your HELOC (for the down payment) and traditional financing to finance the purchase/reconstruction costs of a new property.
Relianz (now Union State Bank) (Brian Berkley is who I dealt with) would be a local bank that would do that sort of thing. Maybe Rose Hill bank, CU of America might be someone to check into.
Your Intrust, Fidelity, Commerce, BofA etc are all probably going to be a pain to deal with as far as paperwork and fees and they are also a bit more conservative. A small bank like Relianz (union state bank) , Equity Bank, Rose Hill Bank should be a little more reactive and able to move a bit quicker if you find a good deal and they aren't needing to underwrite a loan to Fannie/Freddie guidelines.