Griffin Elan Form Graphite link:[ame=http://www.amazon.com/Griffin-Technology-Elan-Graphite-iPhone/dp/B003TYHBN8]Amazon.com: Griffin Technology Elan Form Graphite for iPhone 4: Cell Phones & Accessories[/ame]
I've had this case since I bought my phone, was slammed in my friend's pickup's back hatch, cuz it fell out of my bag and the phone was fine, but the back glass was a bit cracked, just bought a replacement. Easy as that, and it looks pretty dope too!
--- Also, about the charger, I suggest just using the one out the box for your home. And getting any car charger, in fact just go to a radio shack or best buy and you could probably get one relatively cheap, you shouldn't sweat what kind it is as long as it charges your phone..