If you're looking to go the iPod route, score yourself an older 80gb iPod video. These can be upgraded to 240gb, and they actually handle it quite nicely.
HUs with iPod hookups will usually charge the iPod, yes. Some HUs tote "iPod compatibility" which in reality is really just an aux jack to plug the iPod into. These types of HUs will of course not charge the iPod. HUs that can control an iPod will probably cost more than one that's generically iPod compatible.
However, IMO iPods suck. They flatten the sound of my music. I've never liked the way the music sounds coming out of my iPod, even FLAC with Rockbox. My FLAC files sound much more rich and full using a PC vs an iPod. Might be something to consider, read some reviews about. I've tried both my video and a newer Classic, they both sound like flat crud to me.
Because the iPod brand is so insanely popular, you can get a HU w/ iPod controls for a very reasonable price. Crutchfield has quality HUs w/ iPod controls as low as $109.99.
Some connect to the USB port. Some connect to an AUX jack. Some use a proprietary cable.
Lots of options.
Who asked you?
All I'm saying is that if it sports iPod control ability vs Aux in, they try to weasel a bit more money out of you for that "luxury". I can't speak for all decks, just the ones I've looked at... pioneer and the premier line.
I've actually been looking at a KIV-700 or a KIV-BT900
Difference being $40 for a built in bluetooth.
Seems to be closest thing on the market to what I want. $300, video in/out, USB (including hub and card reader support), 3" LCD, 6 lines of text. So many features that I don't need, but all the ones that I do.