I think a good SSD-drive or two in raid-o will do the trick

When I purchased my system it was important with quick load times to keep my team in the same group in Battlegrounds. Two Intel X-25M in raid-0 was enough, my team always occupied the first 5 slots in all Battlegrounds.

I have 12 gigs of ram and have experimented with some games and ram-drive but I don't think it's as good as it sounds.. For one part SSD-drives already loads content really fast, and for the other part you still have to wait for everyone else..

I mean, you can load World of Tanks instantly but why bother? The game wont start for another full minute anyway. I think the same applies to WoW, you can load the raid instance instantly but you still have to wait for the rest of the group, for buffs, cooldowns etc.

I don't think even eliminating loading times completely will improve the gameplay much in WoW, there are so many other things that contribute more to waiting times..

If you do go for it then please let us know how it goes
But more expensive is not always better, I've spent hundreds of dollars on two Killer network cards before I gave them up - even onboard network cards worked way better than the Killer ones