Just so you know crossfire wouldn't really be worth it on that board. The two pci-e slots run at 16x and 4x instead of dual 8x or the better dual 16x. It is also a little cheaper on newegg. There are articles detailing the performance drop when comparing 16x:16x, 8x:8x, and 16x:4x on this site you might consider looking at. I don't have any biostar boards so I cannot comment on quality.
well the performance loss is very minor... for $100 x16/x4 is actually really good and not alot of boards actually have cfx/sli capabilities at $100
heres an actual performance comparison for pci-e scaling on ati cards for the 5870http://www.techpowerup.com/reviews/AMD/HD_5870_PCI-Express_Scaling/1.html
as you can see the actual performance hit is only about 4fps at the most at 1920x1200
tbh, im not really all that worried if instead of getting 60 fps, i end up getting 58fps, honestly the whole x8/x8 thing is more of a money grab for companies than anything else as they make a big deal when it really isnt