If your upgrading to i7 you need the low voltage memory the stuff you linked has 1.8 noted.

Also 4gb is better for gaming, so that wouldn't be as good.

Furthermore, you don't know of possible issues with the new tech yet because it hasn't been tested much.

Besides the q9450 has been taking off the market I'm pretty sure so you'd have to get the q9550.

Personally to me the q6600 is still king because it's a lot cheaper, with a cheaper motherboard, cheap ddr2 all overclocked you can be just as fast as the core i7 for a lot of tasks much cheaper.