What I did was get a tascam 414 4 track and hook it up to my sound card. So I can play with a friend, i directly plug him into a track and me into a track.. but can't separate going into the computer live, so maybe this is not a good solution for you..
I also like to record a session to tape from the multitrack, then process back to the computer.. the range is always better and the sound is thicker.
Ramble..ramble..