You could also take the Pixar approach. Instead of dumping all your cash into one mega computer that will be out of date in a couple years (well… probably not THAT out of date…), just buy or build several moderately powerful systems all to the same spec and set them up as a farm. This way you could get the same components, they would be FAR cheaper (tho maybe not as ‘green’ as far as power usage) and you’d still never need to buy a monitor if you could access a virtual desktop for each of them, or terminal or whatever. Aside from teh cost of a huge megamachine like that, you also have to beware the possibility that it will go down at some point and your renderability will drop to just whatever computer you have to model on. With a netwroked farm you can lose one or two PC’s and not get hit too significantly, and you can always just keep adding more and more PC’s and/or upgrading them for probably far cheaper than upgrading that massive beast machine.
Just think, all you really need is a small HD for each of the slave systems, a few gigs of RAM, a moderately powerful CPU, an ethernet card (or an in-built one) and you’re good to go. Then set up one of them with a large parity Raid server as a master and a file dump for the renders and you’d probably get the same amount of work done as the monster machine at, i would imagine, far less of a cost (if not initially, then surely for upgrading or repairs).
The only thing you’d have to really watch out for is the fact that there are some glitches that can occur whit some systems at render time that might cause some things like particles to not be calculated teh same for each system. I haven’t worked with the baking functions much, but you’d want to bake as much as possible in a setup like that i would imagine (can you bake particles?). There may also be a cooling issue if you do it that way (i have three computers and two of them are generally always on for some reason or another, and my room can get fairly uncomfortable sometimes)
But if you’ve got the cash to get a beast like that for your rendering and you aren’t too worried about the potential risks of putting all your eggs into one basket, I’d say go for it, just make sure all of that extra CPU power actually gets used. I don’t know if Blender’s internal renderer will use a multi-threaded setup like that (and i dunno much about the multi-core CPU’s architecture… do apps have to support multi-threading to take full advantage of those as well?) and that’s the sort of stuff you’ll want to be totally concrete about before you start laying out the cash.