Any of the mid-range Alpine decks are great. If he wants iPod, I'd suggest looking for one with full speed iPod interface. The older one's which require a special interface unit are really hard to navigate.
I put a lot of stuff from www.woofersetc.com
. They usually have great deals and quick shipping. Their pricing on the decks are decent. Their pricing on speakers and amps are killer.
If you are still deciding on a sub, I'd suggest the JL Audio 10W3v2. I just put one in my boat, and it sounds amazing. It only needs a .65 cubic inch box, so very little space. My box is 18" x 11" x 9". These can be had at the above sites for around $150.
My only suggestion for amps is look at the size of the amp. I didn't do this, and the amps I picked up where huge. I still love them, but they required a lot of space.