I have just done both of mine. The outer swivel bearing can be bought separately for about 20 british pounds from splat shop, the needle roller was 6 bucks from a SKF bearing shop. Couldn't get the inner bush separate. I have replaced the needle roller with a brass bush, will see how that goes soon ( wanted to take up some play from a work inner bush, I also have another roller bearing setup that will do away with the inner bush to try at some time).
The Hell Team in Australia have a listing for the whole assembly but it is pretty pricey at 175 AUD.