Try ebay. I have a set of Sibex from ebay, scores a bunch of White Bros a while back and have a Spicer ti bar. The Spicer is pretty similar to the Sibex, though probably not quite as nice. I use it on the bike I ride most, however (Kona Score), and it functions very well...no issues, despite the pictures I saw here recently of Spicer ti forks.
spicercycles.com
If you can't find them just write Gene and ask if he has them in stock. I believe they're 129 USD.
spicercycles.com
If you can't find them just write Gene and ask if he has them in stock. I believe they're 129 USD.