Basic Dedicated E-Comm. You definitely want a carrying case for your laptop. If you don't get one, you'll quickly have a beat-up laptop.
Cases usually come in nylon or leather.
The nylon ones are cheaper but are usually thinner and don't offer as much protection. The leather cases I've seen are thicker and actually end up weighing a few pounds. You may not want a leather case if you've spent lots of cash to make sure your laptop weighs only 4 pounds. Whatever you do, don't get a case that makes it obvious that there's a laptop inside it. Thieves love this and laptops are prime targets because of their small size and high value.