Why does it have to be harddrive based?

There are only a few of them with HDD in them, and they are not that impressive. All the good ones just use the SD cards that come in them.

My personal favorite at the moment is the Navigon 7100. The mount is gorgeous, it has Bluetooth, "reality view", text to speech and more.

For iPod, consider the Alpine EX-10. It's $199 and combines a Bluetooth carkit, Bluetooth Audio streaming AND an iPod interface. Connects over line in or FM.

Backup camera is easy, there are loads of them, but all the rearview mirror screens I've seen are ugly. Most of them also don't have the compass or electrochromatic dimming.

DVD; Check Ebay. You'll either get $500/each high quality good leather ones, or cheap $300/pair ones. Be sure to check with Honda as some vehicles have active head restraints that may not work properly with headrest DVD screens. You'd be better off (and cheaper) with 2 DVD screens and a few headrest mounting systems.

Oh, and there is no such thing as "the best minivan", they all suck