Desktop HTPC Combo Question

[lavs23]

This is my first post, I recently ran across MediaPortal and am liking it so far with what I have tested out on my laptop. I'm currently running XBMC but my XBOX is sooo loud it's distracting when watching movies. I'm planning on building a new desktop computer in the next few months and had a question about graphic cards and running MediaPortal in the alternate display.

Has anybody setup MediaPortal to run in the extended display?
Would using a remote control even work when I'm operating the desktop's other software? It looks like the Hauppauge remote has the option to keep control after mediaportal loses focus which would be great.
I was looking at sound cards under Vista's Sound Mixer program, has anybody set a sound card up so that Optical out plays MediaPortal while the regular sound card outputs play everything else. Not even sure if there is a sound card that supports this feature or not.

Thanks for any help!

My preliminary setup includes:
Hauppauge HVR-2250 (When it comes available)
GeForce 9600GT (Maybe overkill?, not playing games but will have a 24" widescreen monitor with possible photoshop/video editing and 1080p out to TV)
Q6600
4GB RAM
bluegears b-Enspirer