I'm actually in a decent sized room, probably like 30 ft by 20 ft. I've had some luck with some room mics placed 10-15 ft out from the kit. I guess I'm just worried that I might get too much reflection off the ceiling if I used ribbons as OH, so if/when I do get some ribbon mics, I might have more luck using them as room mics rather than ribbons.
I do like your suggestion about the Glen John type set up. I haven't tried that yet.