You want this to be your backup plan if things take longer than anticipated, you do not want to dip into personal credit cards so i would use a heloc to help with down payment but try to keep a nice available balance on a heloc as your insurance policy. 

If you've not read Debt Cleanse, you should.

Also putting a business card and flyer on the door could work.

To answer your questions here though:Alternative options - I was going to sell all my stocks and etfs, take out a HELOC, and some credit cards to try to shoestring together enough to the deal without a hard money loan. 

And how much is your debt service, around $6,500? 

Or paying off my debt, while I provide them with a nice house to live in instead of an apartment. 

I make around $110k+ per year, live off around $75K, have a mortgage ($1900/mo for rent, escrow, tax), around $40K in equity, and no other debt. 

A good DST would absorb the rest of your debt nicely.

I imagine the only way it would be possible is to do the bulk purchase in cash, sell off a couple and then put debt on them?

@Daniel Tanasa   Unfortunately that is not correct when it comes to mortgage debt.