However, I will using a property manager and am not looking for the ability to choose/screen my tenant, receive monthly funds, etc.

Just the newest fad being hawked and sold at exorbitant prices by the TV Gurus.Under the 2018 Tax Cuts and Jobs Act (Trump Tax Cuts) the S -Corporation has the best tax treatment.In Illinois you should buy properties using a Land Trust.

What would be the most efficient way in using a 100k HELOC?

I've found by using a less direct approach, most folks are more likely to respond in a positive, helpful way. 

If you still are a California resident, you may want to consider using a tax preparer who is familiar with California and its excentricities (and obviously someone who is strong with real estate and its unique tax issues) rather than someone located where your investments are.

I never thought of that because I don't plan on using a property manager right now.

One of the companies I've looked at using as a property management is called Vacasa. 

I am buying a property and will be managing it myself, but the current owners are using a management company.

Using a comprehensive computer program will produce accurate operating budgets.

Using a comprehensive computer program will produce accurate operating budgets.