If it's currently an STR they should be able to provide you with the p/l statement from prior years so you can see gross rents, operating expenses, average daily rates and occupancy levels.

Guests provide revenue and guest provide Reviews. 

Quote from @Malcolm Brown: My real estate agent provides listings (multi family homes).

Would banks typically provide a HELOC on an investment property, and if so, what terms should I expect?

Happy to provide more details.

It depends on what you want to invest in.

HELOCs on rentals are rare, and depends on where you are located.

So, your focus may need to pivot from high rental cash flow to little to no cash flow as a rental with an appreciation upside.I would recommend taking your $150K to $200K and securing a solid equity position in something that will cover its expenses and maybe provide a small cash flow, but then is poised to appreciate nicely over the course of the next several years. 

Quote from @Iris Wu: @Steve Mitrano, Hi, Steve, do you mind providing an update on what you end of doing in this case?

Maybe concrete single-family 1-4 units depending on the price point and cash flow.Also there is no real MLS in Puerto Rico you need to find an agent for each area you want to look at.