The A8 has OK graphics, nothing brilliant as its only a 6550 I believe, but enough to play games like COD, BF3 and the like at mid settings with AA turned off.
With the extra money you could get another 6550 or similar in crossfire on the board, and no it wouldnt be slower.
http://www.overclockers.co.uk/showproduct.php?prodid=GX-267-SP&groupid=701&catid=56&subcat=1984
EDIT: Someone correct me if I am wrong but doesnt the cards have to be the same if cross fire?
I am confused ? Two 6550'S or is there a different 6550 type?
Stulid unfortunately where I am now is terrible inter webs (using a phone on edge) I am currently unable to load the review fully.
Thanks again
~ElGimpo