I'd go with the Alpine if it were me. MP3 capapbility is a big plus. On a side note, I've heard that the Nak isn't reliable. I've noticed people complaining about the loading mechanisms and other tid bits on other forums I frequent.

As for an amp to power your Focals, get something with atleast 75 watts x 4. PPI, JL, Phoenix Gold Ti, are some of my recommendations. Arc Audio is super nice if you have the flow....