Sound card/canvas recommendations

Looking to upgrade the integrated sound card (!!!) on my P3 (500 MHz)
to something that actually works and sounds better.  The following
seem to come up quite a bit:

Edirol SD-20
Audiophile 2496
Delta 44 or 66
Echo Mia

I want to be able to record live music, from microphones through a
mixer into the computer, as well as multi-track record from a synth. 
I am looking for the best playback (ie. realistic sounding
instruments) as I can get for not TOO much money (<$400US), and with
minimum latency, esp. for recording while playing back.  So...,

Am I looking in the right direction?
Any preferences?
Any other options?
Do any of the above lack something that I might want - I have a
midi-USB connector, so I understand that the latency should be
comparable if I go with a sound card that does not have midi, yes/no?

Thanks
Martin Lacoste