2. You are going to want an Opus. Whats the clock speed on your CPU?
3. Both, some people pay a lot more for the laptop hd because they think it is worth it. Although most people without them have never had a problem and save a lot of money. Most people think that if you mount the HD vertically is sustains the least amount of shock but some people think that it doesn't even matter. Several people have their HDs mounted on their subwoofer and never have problems.