I am going to buy a new PSU of CORSAIR for my IBM thinkcentre desktop. My previous original PSU was of 230 watts. I have not added any hardware in the CPU. It's in same condition as it was when I bought. On that basis, please suggest which power supply of Corsair and of how many watts will be suitable for me to buy, after referring to the under given weblink. http://www.corsair.com/en/power-supply-units.html Thanks.