I also highly recommend the Bogen Quick release C-clamp. It fits over pipes, and othe surfaces far wider than my superclamps, and it also has a built in 5" extension arm. I found Adorama to be cheaper than B & H for most Bogen items.
http://www.adorama.com/BG649.html You can hang your bar in either direction, with your mics above or below. This can also be used with some of the extension arms mentioned in the other thread, such as the Bogen 5" arm. It also helps to have the Bogen Rapid Adaptor,
http://www.adorama.com/BG3102.html which allows you to mount your bar, either horizontally or verically. You will need a 5/8" 27 thread adapter for this. I DO NOT like the Bogen adapter. It seems to spin on the bottom of the Rapid Adapter, and the threading is very short. My mics came with threaded adapters that I use instead.