Just to chip in again re: thunderbolt port.
IMHO this is a pink elephant of an interface, I have it on my MBP.
Third party support for it is limited and peripherals seem very expensive.
Thunderbolt ain't ready for prime-time. It's fine if you're only running one or two low-bandwidth devices, but as soon as you start to push it, it starts to get flaky.
Not sure what you mean by flakey. It's pretty solid in my experience & I've done a lot of testing with it. Yes, it's a bandwidth sharing PCIe bus on a wire, but it's far faster than anything else out there right now. As long as the devices you're driving have a decent driver, you shouldn't have issues.
What I mean by flaky is that devices fail to initialize or be recognized. I have now 5 of the new Mac Pros, and all have three monitors -- two Apple 28" plus a large-screen monitor (connected HDMI), an ATTO FC1082 or FC2082 Fiber Channel 8G adapter, and a G-Tech 4TB thunderbolt drive. The problem is especially pronounced if
anything is connected on a Thunderbolt port along with one of the Apple monitors or with the fiber channel adapter.
In reality, there are only three "channels" (for lack of a better word) of Thunderbolt on the MacPros with two physical ports on each. One also drives the internal HDMI port. So, it's important to try to figure out how much bandwidth each device is going to use and attempt to balance the load. I never had any such problems with the MacPro towers with PCIe cards and Firewire800.