just my thoughts man ...
if you're new to *nix or linux, then dual-boot if you need those "reqd." things.
soon, you'll be able to figure out how to get those things running too. so, don't hold back, partition, some space for linux, get a distro which is easy to install (i always suggest 'libranet' cos it's debian-based and easy to install) and not some distro which might require some extra time. i wouldnt suggest gentoo/debian/slack if it's the first time for you, but if you have some experience before, might as well, huh?
have fun.
dual-monitor shouldnt be a problem to setup once you get going...
as for napster ... no idea.