I do #2 for the interest savings. Talk to accountant about new tax laws and SALT concerns. I believe since you are using it for business it should be fine and deductible state and fed tax returns should be looked at.
We did this and it's an easy way to raise $ for a down payment on an investment property. Careful of the interest rate however as some HELOC interest rates start low and change after a certain term.
I would definitely consider a HELOC on your personal residence. The closing costs are MUCH lower (sometimes in the neighborhood of $100), fewer hoops to jump through, and you're only paying interest on the money you're using. You can take 75-80% HELOC, and if you're only using 40%, that's all you're paying on.
Interest rates will be a bit higher and are variable... but if it were me, that’s probably the direction I’d go.