Sound card recommendations?

[kwatson6 at austin.rr.com]

Glad I stumbled upon Ubuntu Studio.  I've been through a terrible time trying to get sound working with Linux Mint and Ubuntu 8.04.  Unfortunately, my Creative SB X-Fi card doesn't support Linux.  I've decided to replace the sound card, and am hoping someone on this list can make a recommendation.  

I plan to install Ubuntu Studio when I get time this weekend, and work from that distribution.  I write and arrange music (currently using Sibelius on WinXP), and edit digital photography with Photoshop CS.  Looking forward to the linux environment.

I need the card to work with both Ubuntu and WinXP Media Center Edition, with these general requirements:
- 5.1 speaker capability
- front mic/line input
- front headphone output
- front MIDI ports desirable (I have an adapter that works through USB in Windows)
- 100 Hz S/N
- 20-20kHz freq range
- decent onboard synth

Thanks!

Details:
- Dell XPS 400 w/Intel Pentium D 2.80 GHz chip
- 4GB RAM
- 2 HDD (sda 160 GB, Windows; dual boot with sdb 500 GB, Linux)
- EVGA GeForce 8800 GT video card