Welcome to the forum, gallinazo, however I don't necessarily think the Stereophile board is the best place to get answers to these questions.

While I am sure there are plenty of folks here who enjoy home theater and video gaming the focus is really on musical reproduction, and then with the emphasis firmly on straightforward stereo ("2.0" or "2.1"). Things like "Crystallizer" and "Simulated Surround Sound" are generally regarded as the work of the devil, I suspect both were developed very much with gamers in mind and don't really help the cause of audio fidelity.

Now, if your question had been "How do I get the highest fidelity two-channel sound within X budget?" you probably would have had ten responses by now and a lively debate about the relative merits of Squeezebox vs USB DAC would have ensued.

I hope you get some helpful answers to your questions but I would also recommend you post on some PC or Home Theater Boards to cover all the bases.

Good luck!