Get a paired set of graphics cards for outstanding performance. Nvidia also has a new on-board chip set (sorry I don't have the info at hand and am rushed)that uses both graphics and cpu cores. 2, 4, 6, 8 cores are the emerging trend. A dual core handles things well at present but a quad core now is advantageous for video editing and graphics. The 6 and 8 core boards are where the future is headed but apps have to be developed for them. Most will be video related and gaming will follow right with them. Four cores is going to be fine for some time at present anyway.
The Sony PSP introduced "cell technology" which is multiple (I think it had 8) integrated cores. In the future, the motherboard will be more like whats in your phone with multiple cpus embedded and designed to network. Computer power will shoot up as miniaturization and function have scaled up exponentially even in just the past few years.
Phenom is great and I am a huge AMD loyalist (someone has to keep Intel's prices down).
With the exception of the graphics card you have made a great system here and the prices look like you did some comparison shopping. Make sure you get a good PSU (power supply)...no less than 750 watts. It will use power more efficiently at lower usage levels and not drop your current at high ones which is a huge hidden cause of failed boards and power supplies. The new graphics eat energy. On the flip side the new cpu's effectively adjust core and fan speeds and use a lot less power. Its the difference in a microwave and a tv now. An old system running at today's benchmarks would require a cooling room ; )
FYI...professional surveys in ONLY the past two years show an average laptop critical failure rate (meaning it stops being usable and has to be fixed) of 1 in 3...33%. A desktop is modular with often reusable parts--way better choice. Get yourself a cheap tablet (the Cruz tablet http://www.cruzreader.com/tablet.php is a great deal for the price) and you'll be in portable nirvana.
FYI--there are a lot of tablets out but the Cruz is a great companion for a desktop without spending a fortune.