Hi marcusriv, having a search for the Thermaltake tr2 550, it would seem it is a dual +12Volt rail unit with one rail being able to deliver up to 15 amps and the other 14 amps which is actually very low, especially for a power supply that is rated as a 550 wattage unit. Since the +12Volt rail is where the most power hungry components like the graphics card and CPU get there power from, it is important to have a power supply unit that is able to supply enough power from the +12Volt rail for the system at hand.
So, your power supply is a dual rail unit that is able to supply 15 amps on one rail and 14 on the other. However, unfortunately it is not a simply adjective where you add all of the rails up to determine the output of your +12Volt rail. You can load the rails up to there maximum individually but you can't load them up to there maximum simultaneously. It will be less than 29 amps. Now, I'm afraid I can't find any information regarding the exact maximum output of the +12Volt rail for your particular unit. Though, to be on the safe side, let's say it is able to supply around 25 amps off the +12Volt rail.
Regarding the system that you are looking at running. The Intel Core 2 Quad Q6600 will consume around 100 watts which is about 9 amps. The Nvidia Geforce GTX 260 will pull a maximum of 200 watts under full load which equates to 17 amps. If we then add a couple of hard drives rated at one amp each and then some for the extra headroom, you are looking at around 31 amps which your power supply unit won't be able to provide.
I'm afraid you will be looking at a new power supply unit. The power supply's that Chimerical has mentioned are all very good units from reputable companies. It really depends on how much you want to spend if you are willing too.
