help me to for buy new motherboard

hi

my name is dimitris


i have one core 2 duo 6400
but i want to buy new mainboard for to be and later in the future(quad
core)
because i want to buy the ati r600 and to do later in crossfire
i have seen 4 mainblorads

Dfi
ICFX3200-T2R/G (775,DDR2,RD600)



Asus
Commando (s775,i965,DDR2)




Abit
IN9-32X-MAX WiFi (s775,DDR2,680i)


asus striker xstrem,e






which from these motherboards is good for the ati r600

and which motherbord can be crossfire with 2 ati r600 in
the future

please;;
can you help me please;;
in this problem i have;
what you recomend me to do;;