There are also online platforms that will handle managing security deposit compliance, refunds, etc. like rentable.com

Anything else is luck and relying on luck is gambling. 

On-line Auction Foreclosure Website.

Does anyone know of a lender that will give a HELOC on an investment property.  

@Shiloh Lundahl come on man, really..... 

Regardless of what you do to the important stuff on a home the avg consumer still wants to see granite countertops lol Did you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?

Generally yes a HELOC will go off your personal finances so qualifying is generally based on your income, liabilities, and credit. 

Many of these platforms integrate directly with QuickBooks Online, which I use for my clients.

For your question on background, credit checks etc - what is customary in your area?

Hello, I'm in the process of purchasing a single-tenant commercial building, and I'm looking for recommendations on property management software.