OK Great. Thanks Jazz.

So hopefully that's the plan sorted now. Reckon I might get stuck along the way, but i will give it a go.

So am i right in saying I need NC ones. So that when it detects something it opens and breaks the circuit ?
I will have to ensure that the aluminium frame of the router won't cause false triggers then on the prox switches.

Does NPN or PNP matter for my purposes ?

Do these look like they will do the job?
http://www.ebay.co.uk/itm/1-5Pcs-Ind...U0u32s_xiK0nkw

Thanks again for all your help. Couldn't of done without it.

Cheers
Martin