Tonight? You posted in the middle of the morning, futuregirl!
I don't think Rubinstein recorded the etudes. My favorite recordings of the etudes are from the dark ages before stereo, before LPs, and even before studios recorded music to magnetic tape. If you don't mind the sound this produces, I recommend the recordings of Alfred Cortot and Wilhelm Backhaus.
If you need things like stereo, freedom from hiss and crackle and so forth, your best choice is Pollini in my opinion.