^^Before you buy the obx, see if you can find an actual mugen one. They're a little pricey, but way worth it....

http://twincamtech.stores.yahoo.net/mugtwinloops.html
^^That one's $745, but I can't really tell by that pic if it's legit.

For a site I KNOW is legit mugen stuff... King Motorsports has one... $830 for it...

http://www.kingmotorsports.com/category.aspx?cat=6

Scroll about halfway down and you'll see the civic sport twin loop.