Case: Lian Li makes some great cases and that one sure is pretty, but $220 pretty? I guess if you make the rounds with it, but even then, that seems like a lot to me to spend on a case.
Power Supply: I have no idea what kind of power this system is going to pull so, better to be safe than sorry, no?
Processor: Ooooo, I am very, very jealous.
I'm a big AMD fan, but if I had the money to put together a dream system, I would definitely get myself an x6700. Sure the x6800 is the flagship processor, but--and this is just from what I've read, the difference in performance really doesn't justify the jump in price.
Motherboard: I don't know near enough to offer advice here. It seems to me that if you don't plan to go SLI, then don't get a board that offers SLI as it might save a little cash to spend elsewhere. However, since money doesn't seem to be an issue and you're not sure, then...go for it. I'll only add my generic bit on choosing a mobo--- Just make sure that the board you choose is going to be able to handle everything you want to attach to it. Since this is a first build...check and double check.
Memory: I'm with plaid on this one. It seems more for less--even with the slight performance difference that you may or may not notice-- would be the way to go.
Hard Drives: I'm going to echo Dilbert. Again, more for less seems the way to go.
Sound Card: Again, I'm going to agree with Dilbert. A nice sound card is a nice sound card, but in this instance it seems you're paying the premium for the brand.
Video Cards: Nice. That's a monster of a video card. If you have doubts, maybe you should visit the video card thread or drop Lasereth a PM. He seems to be the 'go to' guy when it comes to video cards. I've bought two based on his recommendations and both were winners.
Monitor: I have no problem with LCD monitors and that one looks very....very nice, but I'm not a big gaming freak. I spend most of my gaming time in the Civilization series or the Sims 2 with an occasional foray into an MMORPG or FPS. I should say that a number of my friends who are into hardcore gaming swear by CRT monitors. If there's a local place you can visit to see for yourself the differences, then it's a trip well worth taking in my opinion.
As for cooling...I imagine it's going to generate a lot of heat and strategically (did I spell that right?) placed fans should keep you running fairly cool. I'd probably invest a bit in a quality aftermarket heatsink/fan for the cpu. It's going to take a bit of experimenting to find the right combination to keep everything cooled properly. And you'd do well to invest in few fans of various sizes--if only to have them on hand just in case. Just remember, more isn't always better in this case.
If you're feeling feeling particularly frisky, maybe water cooling is the way to go. I've don't water cool myself and probably won't until my next big upgrade, but it seems the way to go if you want to keep things cool and, more importantly, quiet.
Since this is your first build, I'd suggest you double check and make sure that you have all the cable you need. For the most part it's not a problem as most will include the necessary cables and connectors, but it doesn't hurt to double check. After all, the one time you don't bother to check will be the one time you won't get it.