Browing the Alpine site they got some players with ai-net and some that say ai-controller...whats the difference? and for the ipod it has to be Ai-net right?

Ai controller would usually be a head unit of some sort as in "Master Controller". "with ai-net" would mean that it comes with the seperate ai-net unit which everythiong else would plug into.
The IPOD units from what I have read will only work with the ai compatible unit which have been produced starting this year.