If you're looking for game support and to offload CPU workload, X-Fi seems like the way to go.
As for the digital output, I would say in most cases that really doesn't make sense to use. Unless "Stereo speakers" means in the process of upgrading you're going with a really serious sound setup and would like to send digital to your receiver / pre to have it decode and convert to analog.
For computer speakers, you're going to be in better shape usually if you use analog. The analog output quality on a card like the X-Fi is going to be pretty darn good and should be better than conversions you'd get from sending digital to a set of computer speakers to have it change the signal to analog.
Anyway, I think you can configure the "flexijack" to output digital from the Xtreme Music.
For the front panel thing, I guess that might be useful to some people, but it sure doesn't seem to be worth it to me.