I went in to the shop today and they actually have a box of U brakes and parts. I found a Tecktro brake and installed it and it looks like it will work. It is a little less beefy than the Shimano part but should do for this build as the bike is set up as a street/ beach cruiser. The end of the lever arm is REALY close to the chainring but does clear it. I will post pics when it is finished.

Thanks for the comments folks. It is nice to know that others have information to share.