Sata Drives -> I recommend seagate....haven't had a mechanical problem with them....ever....unlike maxtor and wd......
Power Supply -> I recommend a Turbo Cool unit.......if you really wanna go crazy get the Turbo Cool 1100 watt
http://www.pcpowerandcooling.com/products/viewproduct.php?show=TC1KW
A reliable power supply is very important....if you dont plan on going with a turbocool....then I suggest buying one thats very heavy. Heavier unit usually mean better transformers.
I guess a nice case probably like a thermatake.........
I would also recommend a workstation processor, like a opteron dual core......
Finally, I would liquid cool the thing.
Get a liquid cooling kit....processor waterblock, chipset waterblock, hard drive waterblock, videocard waterblock.....you may need assemble you own kit with 2 radiators......liquid cooling is sweet....
If you're worried about you components getting soaked and fried then get FluidXP+. Its a non conductive glycerin liquid that can be used as a coolant. Fox news showed a laptop running submerged in it. Also, i believe they have some cool videos on their web site too.