X51 R2 upgrade question

im looking to upgrade my GPU from a 1gb GTX 645 to a 4GB EVGA 960( power draw of 160 watts)  i already know the card im looking at is 1 inch to big so im going to re build the pc into a new larger case and that i will need a larger power supply as i currently only have the 240 watt brick( yes i know there is a 330 watt i can buy but i think that will not work so ill have to get a  normal PSU)  . ive been reading up a lot and it seems the GTX 960 is compatible with the motherboard. my main question is what is the exact name of the motherboard used in the X51 R2 because for the life of me i cant find a solid answer on google and can that specific motherboard handle lets say a 600 watt power supply  or is that to much. thank you for any info you might have as this will be the first time i really put a pc together/upgrade  or anything like this