Snd Card Vs. Interface? Options

[meadows.83]

I have 3 questions.

What would be the major drawback of choosing a quality sound card
over an interface?

Do you think a powermac g4 w/ an m-audio sound card and pro tools free would be a decent
budget setup?

This one's kind of off topic, but, I tried using pro tools free on a slower pc, and recording was
choppy, and i couldn't hear what i was playing until a second later. Is this what is referred to
as latency, and do you think this would happen with the g4/m-audio/pt free setup?

Thanx for your help.