Also if I wanted to SLI with another 8800gt would it have to be the superclock edition or could I just get the normal 8800gt. Thanks
It will work fine, but your superclocked card will work at the normal 8800GT speeds.
BIOS flashing is perfectly safe IF you know how to do it. As long as you follow the instructions perfectly, everything will be fine. You're using NVflash, correct?