I'd second that (from the iPod lovers). I have a 20Gb and 40Gb iPod and my Mrs has a Mini. She always nicks my 20Gb one as the Mini's too small so I now have migrated to the 40Gb.
NB - the 4Gb Mini's 3.7Gb really, the 20Gb is 18.5Gb really and the 40Gb is 37Gb really.
Also, the software on the iPod Mini and the new iPod 20/40Gb is identical.
Don't bother with the iPod photo - it's way too expensive for just a colour screen.
For the extra £40 squid it's worth going for the 20Gb. You can get all the iPods from the Apple Store -
http://www.apple.com/ukstore and if you don't mind the wait they'll even laser engrave your name on it too.
Speakers - personal preference. I'd audition them first to be honest. I have some JBL Creature II's I take with me if I want music out and about
In the car I use an
ice-link but am soon upgrading to a
Screen-Link when it's released to go in the 407 to connect to the sat-nav.
In the beetle I use a belkin auto-connection kit which works a treat and goes in the tape deck head-unit.
Mark.