Replacing my faulty motherboard, need suggestions pls

Hi

i recently got a xfx nforce 750i which turned out to develope a fault, so i returned it and i was provided another one, which is also faulty.
Now i am getting a refund and looking for another motherboard,
Since i've chosen to go crossfire, it will be an intel chipset with atleast 2 pci-e x16 2.0 slots
i would also like it to be a good overclocker
my set up:
Q6700
4GB corsair xms2 1066
Radeon 4870
AC freezer xtreme

Here are some i've chosen:

http://www.okobe.co.uk/ws/product/ [...] 1000006684

http://www.okobe.co.uk/ws/product/ [...] 1000010007

http://www.okobe.co.uk/ws/product/ [...] 1000008876

http://www.overclockers.co.uk/show [...] ubcat=1050

i don't want to spend any more than £125 (i'm on a constricted budget) but im sure i can get something decent.

Also, if those 4 motherboards are good, which is the better one?
the 3 asus ones seem pretty similar but 2 of them have the x48 chipset, which is meant to be better..i dunno
help appriciated

Thanks in advance.

As AMG said, the X48 is better for crossfire because it supports full x16x16 CF where the P45 only supports x8x8, however, the real-life performance difference isn't really big (5-10% top).

All P45 boards will perform about the same so check the features because they are the only difference between the £60 boards and £120 ones.