I have had great luck on HAR 3 times. Then once I find a place I like, I use this place (http://www.eccie.net/showthread.php?t=601713) to fill in any blanks I may have on my application. It works like a charm.
I would avoid renting from a hobbiest directly, while it may work out great, he will have leverage over you and it is also opening him up to liability issues. Allowing someone to use your space to conduct this type of business is a crime in its self.
Also the further you go into the suburbs, the harder it is to be discreet. I will only work out of buildings (condos or lofts). No houses or townhouse for me.