My budget is $1100, unless the above parts will not work well with the new setup. If they can't, the budget goes up to 1400-1500. I would prefer either a 4870 or 4870x2 GPU or just 2 4870s. What I don't know is if my current power supply will work with an I7 setup and one of those cards. I would think it would be fine for the 4870, but the x2 might give it some problems.
Now, the bad news is about the PSU. Your PSU is labeled incorrectly. It claims 650W but only delivers 18A+18A on the 12V circuit, and I'm pretty sure it's not even 36A combined. A real 650W PSU like Corsair's delivers 52A, for example. A 610W PSu like PC Power & Cooling's delivers 49A. I think your CoolerMaster would do for a HD 4870 1GB card, but not for a HD 4870 X2 or for HD 4870 1GB Crossfire. I'd recommend you get a PC Power & Cooling 750W. ($90) http://www.newegg.com/Product/Product.aspx?Item=N82E16817341011
There's also the Corsair 850TX, $120. It may be worth it if you're planning to add lots of hard drives and a TV tuner or two and so on.