Help!!!!! :D

So what is the difference between these units? Essentially they all do the same thing - play your iPod, albeit in limited fashion when it comes to song titles - but they all allow for song control/fwd/back/shuffle.....etc.

I have been wanting to get my iPod hooked up in my new 05 allroad, but after all the searching and looking I cant' see what the real diff is for that model year with the stock Bose Sympany II deck.

Also, the only unit readily available where I have been looking is the USASpec (for ~$280CDN installed).

So what do I do? Do help a noob out :cool: Any info/feeds/suggestions/comments are welcome - wouldn't want to get something then realize that I had a better option.