Koso does have one available in the US through:
http://www.kosonorthamerica.com/The item number is: BB641B34
I ended up ordering the Acewell 2853 with Ace-S4 cable drive adapter to read using the stock speedometer cable. I like the look of the Koso, but it sounds like there have been less issues with the Acewell and I like the idea of still having a tach. I ordered the acewell from:
http://www.dimecitycycles.com/
