you intend to spend 2k or that's your ceiling and you'd like to keep costs down?
I'm just sitting here thinking that you could build a really nice system for 2k. For example a nice big widescreen LCD, SLI or crossfire setup, a higher end core 2 duo chip (especially for encoding), a set of Klipsch speakers, etc.
the xplosion is an amazing soundcard (i have one myself) but i have to say something important about it.
this soundcard is great because it does dts and ddl encoding. (ill explain this in lamest terms)
there are 2 types of surround sound connections, analogue and digital. -analouge you will use 1 cable for every 2 channels, and hook them into either your computer speaker set or A/v receiver.
-1 cable is used and it goes to the speaker set or receiver. in order to achieve surround sound with this connection, the sound needs to be encoded into a compatable digital surround format, like ddl or dts (dts is just a better quality of ddl). movies are pre encoded in ddl or dts, so you wouldnt need a special card that encodes in ddl or dts to get surround sound from them. GAMES on the other hand, need to be encoded by the sound card.
if you intend to use a digital connection, get the Xplosion (i use a receiver setup and it's awesome)
but if you are planning on using an analogue setup, you dont need to spend the extra cash for the xplosion. i would recommend a creative xfi xtreme music instead
you havent mentioned speakers yet, so i figured i could give you a heads up on the sound situation
in my opinion, sound is almost as important as graphics in FPS games. it gives the effect that YOU are in the game, as opposed to looking through a window into the game.
so if you are going digital connection, get the xplosion. if not, i would say the xfi is a better option!
feel free to pm me or just post below if you have any questions.
i would recommend building with the e6600 as you can definitly get it into a build for under 2k and it is really really really fast. i mean it consistantly OWNS an fx 62, not that the e6300 isnt fast, but for 2k build, try to fit in an e6600