Another AMD fan here..... If you have two machines, you might want to consider using the second as a dedicated rendering machine. It would be slower, but you wouldn't care as your primary machine is where you would be busy constructing your scenes.

I agree with Dale on a bunch of things - I have the same AMD Phenom II X4 965 Black Edition cpu on three machines (coupled with ASUS Crosshair III Formula motherboards) and these are rock-solid systems, even when overclocked and performing at speeds just a little under the standard performance specs of the Intel i7. Dale is certainly correct about the things you could do with the money you would save by not purchasing an Intel i7. 

 If I were doing it again, I would go for the AMD 6 core and the newest ASUS Crosshair Formula mobo this time. The tech reviews are pretty positive.

One thing I've learned the hard way over the years - make sure your power supply is much more than you think you'll need. Two of my rigs are AMD Phenom II X4 965 Black Editions, with 6 GB of RAM, the ASUS Crosshair Formula Boards, NVidia 250 (but could be the NVidia 460 video cards), and two sets of RAID drives on each (four total hard drives per machine). I'm using Thermaltake 850 watt modular power supplies on these guys. Over the years, I learned that if the power supply is a lot more than technically needed (150 to 200 watts more than the estimated requirement) , your motherboard and cpu will last a heck of a lot longer, and you can overclock for rendering purposes without giving it another thought. (Personally, I don't overclock very much - wanted the ASUS mobos more for longterm stability than anything else. But, overclocking this particular rig to cut rendering times in half is a snap.))

If you can have only a single machine, an Intel i7 makes sense because your rendering needs are more demanding than your Vue scene creation needs. But if you are able to expand up from an older box, you really should consider an AMD rig.  And, he's surely right about going to a cow system if you are rendering animations, but just using a second rendering computer if you are mostly concerned with rendering stills.

I do disagree with Dale on one little piece. I have a KVM switch that handles two DVI-connector-type monitors and four computers just fine! (A little bit of excessive hardware, perhaps, but I'm making my living with these guys.) My KVM box is a bit high-end and expensive - it is the MiniView Dual View Dual Link DVI (GCS1644) from IOGear. It is supporting two DVI monitors, the four computers, plus a radio mouse and a bluetooth keyboard. (Not to mention multiple  sound systems.)  

Plus, I have an IO Gear4-Port USB Sharing Switch that sits on top of the KVM switch. This little cheap guy hosts a 4 GB Patriot USB memory stick, and one USB connection to each of the four computers. I can copy files from any machine to the USB stick and then just press one of the switches to transfer the files to another one of the four machines. Easy, fast and cheap!

You would not need such a fancy (nor expensive) KVM Switch, but there are several that handle dual monitors, especially if your monitors are standard 15-pin type, and not HMDI or DVI. Just take a look at those produced by IOGear on their website. In a KVM Switch, you get what you pay for. (However, if you go with a KVM Switch, particularly with a good one, try Amazon for the actual purchase, as it is a cheaper source.)