Scenario,
1/4' sound card you say?
Well, I think that kinda defeats the purpose. Use the quietest mixer in the world, but once the signal goes through a consumer sound card, it's noise level and dynamic range are severely degraded.
If I were you I'd stick with your Behringer, but got a nice sound card. Then, I'd put your mixer BEHIND the sound card (to mix from the outputs of the card, not to the inputs). And record your stuff not through the mixer, but through an external preamp. The quality of your recording would be *much much* better, and your Behringer wouldn't mess it up cause it would now be on the monitoring side.
Then, you could use the Behringer to aid you during monitoring, which is pretty much what an analog mixer is used for on a DAW. That is exactly what I do with my Behringer and my Darla 24 and it works very well.
Having your mixer's stereo out go into your sound card isn't generally of much use (unless you want to record the whole band at once and dare to mix all your recordings on the fly ;-).
To sum it up, you've got...
A new Behringer mixer for $500, no improved sound quality cause of your 1/4' sound card input and no improved flexibility
OR
A new nice sound card for $300 and a tube preamp for $100, with much improved dynamic range, much lower noise, and an incredibly wider array of flexibility due to your mixer being on the monitoring side.
Peace
