Go for series 2 if you don't want cellular and want the ceramic back. My series 2 has been great, would never get the composite version on series 3. My original with composite back got scratches, my series 2 is like the day I got it.
My series 2 is pretty fast, not sure what the series 3 without LTE will bring, I think the lack of a ceramic back is a negative.
I assume you can save at least 100.