I'm getting ready to build another AMD system for myself, either 6 or 8 core, and have been doing a bit of research so I'll offer up my suggestions and thoughts for what it's worth.
That motherboard/CPU is a good combo, but do note that the CPU is currently out of stock, so it might be a while before you get it, since the 8 core is new and shipments may be spread out for a while yet as AMD tries to meet demand. It looks like both the 8150 and 8120 are out of stock, so Newegg doesn't have any 8 core CPU's available at the moment.
Nice case and it has a removable drive section in the center so long video cards will fit. It also has a bottom mounted PSU. But for that reason I would go with this power supply instead, since it will have longer cables for the motherboard power connections. http://www.newegg.com/Product/Product.aspx?Item=N82E16817139010
The Rosewill supply would work well as a top mounted PSU, but for your case you will likely need a 6pin and possibly a 24pin power cable extension to reach all the way from the bottom to the top if you expect to do any cable management and tuck things out of sight. The Corsair is a little cheaper too, but it's not modular and doesn't have any lights, so I don't know if that's a deal breaker.
For the motherboard I've narrowed my short list down to:
ASUS - http://www.newegg.com/Product/Product.aspx?Item=N82E16813131736
(the one in your combo)
ASRock - http://www.newegg.com/Product/Product.aspx?Item=N82E16813157267
Gigabyte - http://www.newegg.com/Product/Product.aspx?Item=N82E16813128509
All are the same price, have AMD3+ sockets and AMD 990FX chipsets. So they can use either the 6 core or 8 core AMD CPU's.
After looking at all the reviews and benchmarks for the new 8 core I'm really not that impressed so far. The 6 core 1100T can pretty much hold it's own against the 8 core, depending on what you'll use it for, and it's quite a bit cheaper. If you have a motherboard with AMD3+ socket and 990FX chipset you can always upgrade to 8 core later.
Generally for gaming you want to go with fewer cores and faster clock speeds, as games don't utilize 8 or even 6 cores at this point, or a least I'm not aware of any that do. If you are doing a lot of video encoding, demuxing, remuxing, or photo rendering of Sketchup drawings and other CPU intensive tasks then more cores will give you better performance even if they run at a slightly slower clock rate. For the ultimate gaming system with frame rates you can really brag about you'll want to go with Intel, but you'll pay a premium, ~$600 for the CPU + ~$200 for the motherboard. But then Ferrari engines cost more than Ford engines, quite a bit more. If you don't need the highest frame rates possible while gaming, and the system is also used for other CPU intensive tasks then you'll get a lot more bang for the buck with a 6 core AMD. And it will still post respectable frame rates when gaming.
Right now this is my choice for CPU. http://www.newegg.com/Product/Product.aspx?Item=N82E16819103913&Tpk=amd 1100t
Since I'll be overclocking this quite a bit I'll also have to decide on a CPU cooler that can handle at least 150watts, 350W capability would be better to keep the temps down, like one of the Zalman extreme coolers. But large aftermarket coolers take a lot of space and tend to infringe on the RAM slots. ASUS seems to be the most crowded, Gigabyte is a little better, and ASRock boards usually provide the best clearance as they seem to have the widest spacing between the CPU socket and the RAM slots.
Of course all this is just my opinion...