SSD upgrade compatibility question

I'm planning to buy a HyperX Savage SSD, and I am aware that SATA 3 is compatible with SATA 2, but I just wanted to know how I should connect the drive. Could I use a SATA 2 cable or should I get a SATA 3 one? Also my MB should be compatible with SSDs right? (Foxconn H55MXV)
 
Might seem a silly question but how am I supposed to mount the included 2.5" to 3.5" bracket? I have a Cosmos 1000 case and the 3.5" caddies only have screw holes on the bottom while the adaptor bracket only has holes on the side (aside from the 4 holes for the SSD). Or am I supposed to replace one of the caddies with the bracket itself?