Recording interfaces & software

I'm looking at recording interfaces, but I don't know what will work with what I have.

My current setup:

Recording:

Soundcraft Spirit M8 -> Delta 1010 -> Adobe Audition

Mixing:

Adobe Audition

I really like having faders and knobs to play with when mixing. Half the time, I'll route the tracks out to a mixing board to mix, but I know I'm losing some quality when I convert to analog, then back to digital.

Do any of the interfaces work well with Audition? I really don't need more inputs, but it never hurts.

I'm considering moving to the M-Powered Pro Tools. Any big advantages of PT over Audition?

Sorry, I haven't been keeping up on audio equipment/software and I feel like a newbie again. Help!