Cuilinn has them available here

http://www.cuillinn.com/kilts.html

Here is what it says on the site

Formal Hose for evening-wear is patterned, either in red/white dice, tartan, or check patterns of red/green, red/black, green/white, or other combinations. As stated above, white hose are NOT correct for formal wear. Formal hose can have either the normal turnover or can be castellated or vandyked with a wrap or tie garter as shown far right above - very traditional and very much in the spirit of the Highland Gentleman.
Scottish Lion has them as well

http://www.scottishlion.com/cuscaskilhos.html

This is what they say regarding Castellated Hose

Custom-made in a traditional red and white pattern. These hose feature a crenellated band at the top to simulate the battlements of a castle and are held up by ribbon tied around the leg. Finished inside and out, no loose ends. 100% wool.