Electronics 2000

im looking for a basic circuit to control a heat source - 100w light bulb or 80w heat mat.
I need a temperature sensor that when set allows the temp to rise until it reaches this temp then shut off the power to the heat.
The temp needs to be variable and able to be set to differing temps.

This is for an incubator or reptile vivarium.

The do make them already but are so expensive.

Im looking to control either the light bulb/heatmat via a standard UK mains plug.
Reading about it i presume that i would need a relay to switch the power on and off.
Need something that will also have a saftey cut off temp so say nothing over 120 degrees something like that.
Any help or advise would be appreciated.

Thanks

Forgot to mention that i live in the UK.

What about a bog standard central heating thermostat from Wickes or B&Q?
That would keep the enclosure at the set temp

Thanks for the reply? what sort of think are you looking at?

Something like this maybe?
http://www.uk-automation.co.uk/products ... witch.html

or

http://www.uk-automation.co.uk/products ... 620RF.html