Use external hard drive in the car

Hello guys, at the moment I use an Archos AV 700 MP3 player as an audio source. This one has a USB host, to which I can connect an external hard drive, on whose data one then has trouble-free access. So now I want to pack an external hard drive into the car, the power supply is relatively easy, here is a car adapter with 2 amps for the cigarette lighter. But which hard drive do you take? Most of them probably are relatively stoss sensitive. I would have 200GB in addition, but would also be nice 300 or even 400GB, because I really have a lot of music. Since I am working in the field, I live in the car and want to use as much storage space as possible. A car computer is not possible, because too expensive and too expensive. Who has already installed an external hard drive and can give me tips, which record to recommend? Thank you for your answers in advance!