The Midiman
DiO 2448 seems to be the cheapest sound card with digital
I/O and I use it with the OSS drivers, paid for, from 4Front
technologies at
http://www.opensound.com. The card has analogue output
but no analogue inputs at all.
The Midiman 2496 is more expensive but it may be easier to get drivers
working on it.
Looking at the ALSA soundcard matrix and associated doco, the 2496
doesn't have SPDIF support yet. However the 2448 (CMI8738 chip) seems
to be well supported by the current drivers (0.9.0rc6).
I thought that I remembered that the Midiman Audiophile 2496 had been working with spdif
for a while for me at least, though I have the dat on the Delta 1010 in the music room
now.
I know that there was a lot of ups and downs with the drivers and spdif at first.
I did have to cook up my own .asoundrc for it, but that's kind of expected with a
mutichannel chip being used on a simple card.
Tracey