I'm with Dick, use a USB DAC, or one of those USB/Optical converters to a DAC, and then to your preamp. It's much simpler than going for a soundcard, and probably cheaper too. Studio soundcards have many features unnecessary for audio; matrixing your channels might be fun to do if you have multiple systems and switch speakers around often, but it's mainly for studio use in mixing.
Here's another tip. I recommend you go with a network attached storage, so you can move your hard drive -- the noisiest component -- away from your system. You should also consider a RAID backup, because it's only a matter of time before hard drives will fail.
As for software, use anythings; it's a graphical, and ergonomic preference thing. The only thing that matters is that the software allows for correct drivers, which is pretty much damn near all of them. Windows Vista and above the default drivers are perfect, so it's not a complicated process at all. I recommend foobar2000 for it's customizable interface -- and it's free. Monkey Media costs money I think, and offers no real advantages over foobar2000. J Rivers is a bit on the simplistic side for me, it's nothing much to look at, and feels "clunky" to use.