Tascam Us 122, recording my band Options

[jebbels]

I just bought a g4 powerbook. I want to record my band, mostly as a demo, but possably to distribute at shows, if it turns out good enough. I saw that the Tascam us 122 comes with a paired down version of Cubase. I need a recording program . When I've tried recording through the mic input of my comupter the sound comes out crackling and week.Will the tascam improve the quality of the sound I'm recording? Is the version of cubase good enough(non of the adds are very specific about about the paired down programs features)? Our funds are very limited which is why I thought this could cure both my sound quality issue and program needs at the same time.