I use a Guillemot Maxistudio ISIS which works extremely well with CEP. It has 8 ins four outs SPDIF and MIDI. It has a breakout box and goes for 300$ US. CEP recognizes its seperate inputs and outputs. In fact the sound card comes with Cool Edit SE, basically the smaller version. So it works wonderfully. Most sound cards work quite well with it. I would however stay away from the Creatie Labs AWE series cards. They sound horrible in multitrack mode. They sound fine in stereo mode though. I had one for a while and so did a friend of mine, we both pitched them. The CEP website says just stay away from creative labs all together.
MIKE