Check out Swiss Army laptop sleeves. http://www.amazon.com/Victorinox-Swi.../dp/B000HI2WME They provide rigid padded sides to protect against crush damage (e.g. in a crowded case) that extends beyond the edge of the laptop to protect the edges. An elastic suspension system at the bottom protects against drops. There are (or were last time I checked) landscape and portrait orientated models for shoulder bags or backpacks and are reasonably light.
Hard drives are quite rugged and, esp when turned off (with the heads therefore locked) and should be immune from normal vibration and shocks. Most newer PC laptops instantly lock the heads when they sense dropping. Consumer SSDs are slow & small and expensive per GB.