It really comes down to your level of risk, how much you want to spend, how knowledgeable you are with the area, and if you want to be hands on or hire a property manager. 

some of our builders are offering as much as 7 points towards rate buy down.  

Once you find a house that you believe would be a good rental, meaning desirable to your target market of customers (people within a couple of mile radius of the place), and all of the costs of monthly ownership that you can accurately project fall below the rental amounts that you project that you can get from your target customers, then you have a possible business asset that you can use to produce income, and have renters pay down the mortgage, while hopefully it goes up in value at least with the rest of the economy. 

In Chicago, this would be shut down.

The main reason is because local governments are getting quite aggressive trying to shut down STRs and creating new taxes etc for them.

I was just sitting down bored and playing with my BP profile. 

DSCR loans are based off of down payment, credit score and either actual or market rents so it helps to supercharge an investor's real estate goals and net worth.

I would use profits from rents to pay down as I project a yearly COC return of 12k.My question is, would it be wiser to just use heloc for down payment on property and finance the rest of it with a lender?

It will help with your exit strategy...down the road.

@Rein BehlkeYou will need to talk to a lender and usually put some money down if the bank doesn't like the financials.