Thought I would drop my 2 cents regarding rudder bearings, as some time they may not require replacement (or at least not immediately).
Two years ago, in the middle of a 350miles passage the rudder seized very badly after about 100 miles - autopilot could not steer at all and by hand it was very very stiff. Had to hand steer for the rest of the passage - luckily we were a crew of 4. Upon arrival I tried to find a replacement bearing. No one had it in stock and considering delivery time and installation, that meant loosing more than a week of vacation, so I searched the net for alternative "first aid" solutions. One of them suggested to simply oil the bearing.
Crawl into the lazarette and loosen the top retaining band of the rudder shaft seal. Insert between the seal and the shaft the thin red tube that comes with any WD40 can. Spray a generous amount of wd40 into the seal - this is what I had, but I guess other lubricants may be good as well - one of the posters mentioned that they used olive oil because they had nothing else. At first there was no change, played with the wheel back and forth but the wheel was still very stiff. Went to sleep and the next morning the wheel was completely free - even smoother than I ever remembered. Just to make sure I sprayed again after 24 hours.
Continued for additional 500 miles on that trip, have been sailing for the last two years and still did not replace this bearing.
I did make some searches for alternative manufacturers and the 2 that came up were already mentioned in this thread.