C0 stepping vs D0 stepping

I'm looking to build my first PC

I've decided on the i920 - and am trying to figure out if I should jump on a sale price for the C0 or wait a month or two and pick up a D0 when all the C0 CPU's have been cleared out of inventory and maybe MOBO / RAM prices have come down a bit more.

My understanding is that the C0's run at a higher voltage and therefore run a bit hotter - and the D0's run a little cooler b/c of the lower voltage - hence a small bit of extra overclockability.

Can anybody quantify the difference between the two in terms of heat - and in terms of overclockability.

* Are we talking about 3.7 vs 3.8 - or 3.7 vs 4.5 in terms of OC ability.

* For heat - what are we talking about. The room my PC is in currently is about the warmest in my home without any PC. So I'm a tad bit concerned about a massive heating element being introduced - but I really want the i7 so I can forget about my CPU for 3-5 years and build around it.

This system is a big investment for me for a PC - so I want to get this right.

Thanks

I've seen G0 Q6600s struggle to hit 3 GHz, while my B3 (older stepping) is sitting nice and happily at 3.2 GHz.

It's the luck of the draw, but newer steppings tend to perform better. It doesn't guarantee improved overclocking, but it makes it more likely.