I got 1 last question before I head down to simlim tomorrow
:O
Can my 430 casing fit 2 6870 GPU?
Or can my Z68MA-D2H-B3 fit 2 6870 GPU?
and XFX or Sapphire GPU are better?
(Both about same spec..)
But XFX fan is weaker and doesn't inculd some necessary cables that
sapphire inculds.
Sapphire doesnt have life time warranty but have dirt3 game that
comes with it.
Which should I pick XFX is kinda cheaper tho
Edit: do I have to change my MOBO for better vendilation since
mine is mATX maybe ATX is better?
Hi dude...sorry for not being able to reply early as I've had
the impression that everything was settled on your part thus I
wasn't paying any attention to the thread. Nevertheless, here I am.

I hope that your budget is doing okay right now. 
The thing with your casing is, if you've noticed in the specs,
they could accomodate the Radeon HD 5970 card's length. Meaning
300mm (30cm) length max. should be okay.
Unless your HD 6870 is longer than that (which I don't think
so...maybe around 24cm more or less...you ought to check though),
you must look closely again on the specs of your card choice and
adjust accordingly by purchasing the right card for the right mobo
and casing. I hope you are clear on this. Don't rush into buying
anything if you still have questions unanswered or doubts.

For your graphic cards, Sapphire is already good choice made
from the start. If it's all boils down to that $$$$ again, I
guessed you should lower down your expectation for the gaming
experience that you'd look forward to. 
Life time warranties are not always as it seemed to be. If the
card is fried due to normal wear, not even the after-life time
warranty could save it. 3 to 5 years warranty should suffice and
justified for commercial sake. 
My choice goes to Sapphire. If yours' aren't, it's okay though
just look around for new choices, that's all...no worries.

Again for your mobo, I really want you to calm down on this and
go through the process of re-evaluation. Do you have any other
types in your mind? As I've said, do not rush on something you are
unsure of.
Changing mobo because of ventilation is not a bad idea, as long
as it fits your budget then go for it. If you happened to choose
another mobo, could you do away with the integrated graphic (on
board graphic)? Do you think you really need that? After all you
are going to submit yourself to Crossfire in near future. 
Hope this would shed some light. 