Best socket 775 motherboard/cpu for cooling prototypes

[synthetiser]

Hello,
I'm developing a cooling system project which need overclocking, in which an not really an expert.
For now I need to build a prototype in which I don't care much in the calculus performances. The only requirement are that I have a large enough margin in overclocking/overvoltage. The best would be on-the-fly overclocking.
So I wanted to start with low cost socket 775 cpus and motherboards.
What are, for you, the best motherboard/cpus to do such tests?
Thanks

Christophe

 

[Mr.Scott]

P45 board and C2Q's and C2D's.

 

[Nebulous]

P45 board and C2Q's and C2D's.

I concur For more money you can also go with an X48 board with the C2Q's & C2D's

 

[synthetiser]

thanks

- - - Updated - - -

Thank you very much for so fast answer!
I'll try to find some! do you have some address in europe?
Additional suggestions are welcome (not so easy to find by lot, so if we have larger choice it would facilitate our research)
Thank you again! can I do on the fly overclocking with it?