After some research, I chose a dual Opteron MySQL server for my new search box. For storage, I only update the tables once a day, so I plan on putting my data directory on a Linux ramdrive and backing it up to the hard disk after each update for maximum performance.
If anyone has any reccommendations for dual-opteron 64-bit Linux distributions or any experience or tips on running MySQL on a ramdrive I'd like to hear them. Thanks Seth