Hi Ian,
You can get the Nachi brg you mention from RPM Bearing in Boca Raton Florida USA or RPM Brazil. However they have $500 min order qty. – not what you wanted I'm sure.
You can get a 63000-2RS1 standard bearing from any brg/industrial drives house in the world, many very inexpensively. This is the 10 x 26 x 12 brg Robert mentioned.
I have bought similar sized bearings for less than a dollar each, if they are a stock standard size, at surplus and industrial drives houses here.
JD