I had to drive 45 miles from home to find a store that carried them-I have wide feet and was afraid to order without trying them on. My "street" shoes are usually 7.5. Most of my workout shoes are 8. I had to order an 8.5 in Ryka's.
holabirdsports.com is where I got my Rhythm IIs. $68.90 including shipping-it was the best price I could find online (a few weeks ago) and they arrived in about 4 days.