The MBOX 2 audio interface that comes with a full version of ProTools 7 is what im using, there is a bit of a learning curve, but it is the best possible program for multi tracking as it is the industry standard. they will run approx $500 cdn. Pro Tools is amazing, along witha program like reason 3.0 (which is a crazy sampler/sequencer MIDI program) you can create demo (or better) quality songs from the comfort of your own home.

its worth the investment.