Nashbar has frames onsale...
The bolt on hanger is an intriguing one, if a bit inelegant. The bolt on the upper part holds it onto the frame, the axel holds it in place.
I don't think it would work very well because the axel on a wheel with qr's doesn't stick out past the dropout, which the hanger would require.
A couple other things, I'm assuming that the hanger/dropout is aluminum, so by it being bent more than once your already on borrowed time with it. When it does get bent, and put back into place, is it checked with a hanger alignment gauge? If it's done by eye, you can get it close, but it will never be perfect. And if you have better components, any misalignment will be more noticeable.
IMHO, new frame, and build this one up as as single speed.