I was leaning that way, but I'm not able to monitor the project or have a good enough handle on the repair costs to know whether or not I can get my money back out with a refinance to go out and get another place and cover the HELOC.

If so, you’ll need a way to monitor their performance. - annual and turn-over inspections: your handyman can do these with proper direction and a checklist.

I've had a basic security system installed, and the first 12-months monitoring is included in rent (this drops on renewal or for the next person -- a built-in $25/month rent increase for me :-). 

They may be good candidates for financing a property for you, but they are much less likely to be in distress.There are list companies that monitor people's credit scores and send you their name when it drops a bunch.

There are real-time radon monitoring systems.  

Do you charge for monitoring and maintaining vacant units?

My property will include an alarm system and monitoring with the rent.  

Always monitor and make sure the bills are up to date, if not, send a pay or quit notice.

There are usually good local people that monitor those forums and they might be able to share who they have used for this sort of thing. 

Business accounts with personal guarantees don't show up on your credit report.What that all translates to is even if it's a 0% short term loan, it can have an affect on the price of everything from your car insurance to your personal outstanding credit (if you have any).Another thing to consider is credit card companies can (and will) drop your available credit instantly when things go south - I had this happen on a HELOC of all things back in the 2007/2008 time frame.If this is a strategy you want to use, I would also recommend working through a monitoring agency such as creditsesame.com (they have a free portion that I use) to manage the risk.