I think he's saying he want's to tell that rig ^, and build a new one. From the ground up.
If thats what your saying OP, then list a price range and we will put the parts together. The only problem with the current times is the new technologies are releasing within the course of the next 4 months. Intels Ivy bridge is coming out, as well as NVIDIA's kepler. The only problem is there is still yet to be any performance comparisons that are legit for both. If possible, hold out for another 3 months, You can do it with that system, trust me.
As for the Income price of selling that gaming computer as is in 3 months from now:
I would say your looking at the 600-700$ ball park. Considering you paid in total about 800 or more from that system with everything retail. The good think about Intel is, the value of the computer when you sell it is still high because the performance its fresh for about 3-4 years.
I hope i have put things into perspective. If you are saying that your looking at those parts to purchase, We can make you one better. for just a 100$ more. 1 of my 560 ti's performance along the levels of your 550ti. So....Within another year, you need to upgrade your GPU power. and Also as Sadam said, Thermaltake PSU's, Yea not a good idea. I am thinking Corsair or Cooler Master. I have preferred Corsair's Power Supply's. But i Also like the build quality of Cooler Master's so both are good, when buying a Power supply, the main things you need to know is, What the 12v rail ratings are, 1 0r 2 12v are highly recommended (Don't get one with 4 12v rails). Aslo the total wattage. Calculate how much all your other components put together draw by using a Power Supply Calculator. And last but most important standard is the 80 Plus rating, they Rate Anywhere from Silver to Gold (Maybe Platinum?) now adays.
Graphics: Graphics is probably the most important Factor for a Gamer builder. Make sure your Graphics Department can handle the JOB!
Case and Air FLow: I really like that case, I have only used Mid towers and will always use Full from now on, because the one i picked didnt have quite enough Airflow, But i like this case. Your case is perfect for the job, It supports ATX and has plenty of room.
Well that looks about it, RAM looks good (I almost picked that kit)
Good Luck, and come back if you need help!