Pairing up Corsair with other brand RAM like OCZ

Hello all,

It may be a noob question but yeh i dont denie it, im a noob.

i now got Corsair 2GB (2x1GB) DDR2 1066MHz/PC2-8500 XMS2 Dominator Memory CL5(5-5-5-15)
in a P5Q Pro m/b with a E8400 al running at stockspeeds. i gess

but i want to pair up another 2GB with my current rig, i want it as cheap as possible,
and as Corsair is quite expensive over other brands, i wanted to ask if its possible with my mb and cpu to get another brand and pair it up with the corsair, and if it will work?
I saw these were quite cheap:
http://www.ebuyer.com/product/119223 (Kingston 2GB (2x1GB) DDR2 1066MHz/PC2-8500 Hyperx Memory Non-ECC Cl5(5-5-5-15) Unbuffered)
http://www.ebuyer.com/product/142405 (Crucial 2GB Kit (2x1GB) DDR2 1066MHz/PC2-8500 Ballistix Memory Non-ECC Unbuffered CL5 Lifetime Warranty)

there are many others there on ebuyer, which one would you recommend me?

And what if i buy (2x1GB) DDR2 800MHz/PC2-6400 of any brand?
Would it work paired up with the Corsair 2GB (2x1GB) DDR2 1066MHz?
What would happen with the Corsair 2 GB, would it downclock to 800Mhz?
And can I overclock the new 800Mhz sticks with the Corsair 2GB to 1066Mhz?

All weird questions come up in my mind if I buy any other type/brand of RAM than my current Corsair 2GB (2x1GB) DDR2 1066MHz/PC2-8500 XMS2 Dominator Memory CL5(5-5-5-15)

Btw, I was looking for as cheap as possible, as long compatible and stable with my current RAM

Hope you can help =))

L0L the other thread which was posted 10 mins after me has 10 reply's already...
looks like no one knows answer on my question? At least i'm not the only n00 b

Yea, esp on a LGA775 system, 1066 is almost useless.

Sell the corsair and get yourself a 2x2GB kit of DDR2-800 and enjoy.

what do you think of this Crucial 4GB (2X2GB) DDR2 800MHz/PC2-6400 Ballistix Memory Kit CL4 2.0V
for just 35 GBP??

http://www.ebuyer.com/product/166461

thanks =)