Temp Sensor, what do i need and were is it ?

[polo 1.3]

Thinking of changing my temp sensor as lately my temps seem to take ages to get to the "Optimum Temp".
Normally on my 10mile 20-25min (5mins on motorway) drive to work it would take around 2miles for the temp to reach the "Optimum Temp" (needle in middle).
But lately (yes i know we have had some cold weather) by the time i've got to work its just come out of the red zone.
I'm wondering if the sensor is playing up.
I've have a M Reg 95 MkIV 1.3 polo.
I've seen temp sensors on ebay that are green but reading on one of these thread on the forum this does not match the one that you pull out.
Any heads up on which one i need and were exactly do i find the temp sensor to replace it.

[NOZ]

Best to get one from somewhere like GSF to be certain. The temp sensor is in a pipe on the right side of your engine. There may be a guide to changing it as it's a common task so search it in the DIY section. Hopefully you'll find a picture of where it belongs.

[Tim_GTi]

Here's a Guide. Pics don't work though