I bought a Silverline Router on the net. I don't do many kitchens, maybe one a year, if that, so shelling out £300 or so for a router didn't seem realistic. I saw the Silverline job advertised for £70, and as it was described as being 'complete with guide bush' bought it.
Only realised when I opened the box, that the guide bush is 20mm - not 30mm, which is standard, when using a worktop jig. You can't (to my knowledge) buy a 30mm bush for the Silverline router anywhere. Which effectively makes this router worthless.
Save your money, or spend a little more, and get a router that is advertised with a 30mm guide bush - as I did, eventually. You live and learn.