Thanks for the suggestions. This is for a new panel.

I was looking for something like what Ger linked to, but they're bit too expensive to get anything like that in the UK. A bit searching of RS has yielded 502-8637, which is listed as suitable for industrial controls. That's a 10K version, but I may go for a 5K.
I still need to work out the finer details of wiring the panel, but at least I now have the basic components.