The "gold standard" of ankle holsters is the Alessi Ankle holster, made by the late Lou Alessi. I don't know if they're still in production following his death, but they're still available on e-bay & other places Google "Alessi ankle holster" for possibilities. Ken Null http://www.klnullholsters.com/
makes a similar rig, & is of top-notch quality, too. Kramer leather http://www.kramerleather.com/productDetail.cfm?productID=1&categoryID=29
offers this one of horsehide...it's quite expensive!
At less than half the price (new...much less used), Galco's Ankle Glove is a good ankle holster http://www.usgalco.com/HolsterPT3.asp?ProductID=1725&CatalogID=6
. In fact, it's the only
Galco holster I like, or use. My 442 lives in it.
Whatever you choose, be sure to get something fitted to your gun, not a generic pouch holster.