Soundcard and DAC

[Jimmy_The_Clown]

Hey I'm a college DIYer assembling my first decent audio system. I got spoiled installing Legacy systems for an audio company a couple summers ago.

I'm in the process of building the speakers and the amp, so now its time to consider the source.

I'm looking for a PC solution, but can't find much info on what soundcards are worthwhile/moddable. Ideally I'd like something with s/pdif out so I can build a DAC in the near future. The idea of a card with a clock in is really appealing. But it's also important that I can run 5.1 home theatre off of it. Analogue out is fine for the 5.1. Can 5.1 be implemented with several s/pdif out without dealing with audio decoding at the hardware level (ac3, dts, etc)?

I'd like to keep the price range down to $200 or below, used off ebay of course.

I've looked briefly at RME hammerfall and also the M-audio delta 410 or and audiophile 2496

If someone could point me towards a decent DAC design that isn't too expensive (~$150) that would be great too.

The rest of the system is a pair of decware HDT towers (not quite done) and an inverted gainclone a la Decibel Dungeon. Thanks for any advice.

-JTC