I dont know what these guys are like to deal with but they do have some good prices and a lot more parts than the other sites. I guess they are not OEM stihl as they sell on the net. You stihl lovers will love it.
I bought the Baileys 044 top end kit for US$99.00. Seems to be working just fine. You'd have to contact them to see if they offer any other sizes. My only gripe is that they did not include the pin bearing.