I have the white/gray iPhone bumper with a white carbon fiber wrap (on the back only), it looks sick!! This picture doesn't do it justice, but it looks fresh...almost like a Nike shoe LOL
Recently I haven't been too protective of iDevices. I don't drop them, but I took the case off. I'd just recommend good screen protectors though.
Amazon would be my choice, eBay is another one but I personally would trust Amazon the most. I've never used any other than those two I mentioned.
Yes iphone 4 Bumper could be a best solution for it could keep the genuine fashion style of the iPhone, and provide a fully protection, just look at my iPhone 4S bumper...