Raid 0 HDD's offer some performance boost when loading, etc Although to be honest, there won't be a *huge* amount of diffrence, however it should be noticable.

As far as Age of Reckoning, my "sources" tell me that its far more CPU intensive than WoW. Apparently it supports SLI as well, which could make things interesting (WuWu for joo Xzin :P).

Your friends have misinformed you about "IP stacking" I don't think anyone here considers this an issue.

As for an operating system, XP 64 bit or Vista 64 bit. This is the only essential thing for systems with > 3GB RAM. This aside, you'll suffer a performance hit with Vista (due to the extra bells and whistles) however XP does have its own "issues" with Dual-view which cuts performance significantly. In XP the Dual-view performance problem can be fixed by switching to horizontal span instead.

As for extra hardware, Most people just use their normal keyboard, however some have used things like X-keys and such to great effect (Programmable keyboards) But this is considered a "plus".

Good Luck.