I don't see gaming listed anywhere in the intended use, so you don't really need a 5770. Don't get me wrong, the 5770 is a great card and I recommend it, but it's more than you need (not that it's a bad thing). A 5750 would be another good option if you decide to step up to a DX11 card.
Another thing is that the 5770 offers considerably better gaming performance than the 4670. I don't know where the statement about them offering similar performance came from. The 5770 and 4870 offer similar performance, the 4670 is much slower than either card.
Switch the HD 4670 for a 5770. They'll give the same performance, but the 5770 runs cooler, quieter and it's more future proof with DirectX 11.
What "Same performance" ? A 5770 performs like a 4870 and will run many games maxed out at 1680x1050. A 4670 is not even close.
That EVGA E757 motherboard is a white elephant. It is designed for 3 main GPUs in SLI/Crossfire and a dedicated PhysX GPU. It is not appropriate even for a dual card sli/crossfire configuration as it can not do x16/x16 like it should.
If you want to use EVGA, go down to the E756 or up to the E758, but EVGA is a high end gaming board. The ASRock x58 extreme is a far less expensive board that has good reviews and is better suited to your needs.
The PSU wattage you need is basically dictated by the GPU you buy. For a 4670 or even 5770 for a single GPU would be fine with a quality 450W PSU.
Thanks for the replies everyone - I really appreciate the advice!!
I updated my original post to re-iterate that I am NOT a gamer, so the video card definitely does not need to be high-end. Would like to keep the video card under $100 if possible - can anyone recommend a better card that would fit my Photoshop and Video Editing needs?
I was a little nervous about the ASRock X58 Extreme LGA 1366 Intel X58 ATX Intel Motherboard - Retail Mobo based on some of the Newegg reviews, but it seems to be highly rated by Tom's....
Your original 4670 GPU would work great for your needs. Photoshop CS4 does use GPU acceleration, but the 4670 is plenty powerful for that. A lot of people on here have a hard time remembering that gaming GPU's are not needed for all builds.
You should be good to go. Your case has good airflow out of the box. The case and motherboard will come with all the cables, screws, etc... You could pick up some zip ties if you want. I think I got my last assortment of zip ties from Home Depot.
Newegg won't guarantee a particular stepping. I highly doubt they have any old stepping CPU's in stock, though. They move more hardware than about any other online retailer. They don't exactly have i7 920's collecting dust on the shelf.