Replying to External Hard Drive Question

im buying my 2nd one... and i have a few questions

Money is not really an issue, 200 is my max
it must be a bus drive (the computer is the power source)
i have a MBP so USB 2.0 or Firewire 800

1. Which company/HDDs are the most reliable?

2. Should i partion it (to keep time machine from filling it up)

3. how do you backup your files? (movies, .dmgs, pictures, etc)

4. I want to keep a copy of my comp just incase something fucks up, is time machine the best?

so these are just a few questions that ive been thinking about... if there is anything i should know about external drives tell me

if there is already a thread about this, plz link, teh searchbar is bad

thanks NS