Here is a list of external soundcards that was compiled.
Ultimate USB, Firewire, External Soundcard List
I see you must be in Europe somewhere so I don't know what you can find over there compared to here in the states. I have heard the Terratec Aureon cards are supposed to be pretty good but I don;t have any personal experience with them. Keep in mind with any analog output of a soundcard you might have a small turn on thump when windows starts up. If you are happy with sound from the creative card then you could do a delayed turn on for your amplifiers using an I/O USB/serial relay card. Do a search in the Hardware or Input subforums.