External Hard Drive for Music Video Play back issue

Greetings:

I am using a Macbook Pro i7 15" 7200 RPM and use it to do music video play back. I need to get a external hard drive that I can store my collection on that will play back smooth quick and accurate. I know that my macbook pro only has USB 2.0, Firewire 800.

Does it matter which I use for play back? I have been told they make eSATA and USB 3.0 Express port cards. Are those just for the quick data transfer or will that increase the smoothness of my playback when in my music video program. Will it matter if I look for a 5400 RPM or a 7200 RPM? I have been looking into the Lacie Rugged product because I am constantly on the road and need something that can get banged around.

Please help as I have been researching and trying to understand what to spend my money on that will best effect the type of work that I do. Thank you for your time!

You will want a 7200rpm drive, preferably connected by FW800. How much RAM do you have in this machine, and how fast/empty is your boot hard drive?

Model Name: MacBook Pro
Model Identifier: MacBookPro6,2
Processor Name: Intel Core i7
Processor Speed: 2.66 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache (per core): 256 KB
L3 Cache: 4 MB
Memory: 4 GB
Processor Interconnect Speed: 4.8 GT/s

Is that the information you need? I have about half my hard drive on my computer full. Should I use my express port to run ESATA or USB 3.0? Or does a firewire 800 do fine and I won't see any difference going to the ESATA or USB 3.0? Thanks for your continued help!