External HDD (With enclosure) for MBP (HELP!)

Hey everyone i need some purchasing advice with regaurds to external HDDs.

Im interested in getting a speed demon SATA HDD and putting it into an enclosure and using it as an external for my recently purchased MBP, the HDD im looking at will probably be 10K rpm, good for logic studio / pro tools ectect.

Though, im not sure about externals though, what are the drawbacks? Does going through USB 2.0 slow down the transfer rates? Does having Firewire 800 available make a difference to this speed? Whats the best enclosure to buy and am i stupid for even asking?

I guess my question is; can i run a fast Hard Drive externally, in a HD enclosure? And can it be faster than my internal 7200RPM drive? Or is its speed going to be affected by USB 2.0 or Firewire?

Help is appreciated, cause i seriously don't know the lowdown on externals and how they run.

 

Obviously an external wont run as fast as an internal but i'm not sure what the speed costs are. I have an 80gb laptop hard drive in a USB 2.0 external case (which i think is actually faster than normal firewire) and i runs well enough for my needs. I had it full to the brim and it took me less than an hour to copy everything to my desktop. I run DVDs off it quite regularly and it runs fine.

Grand Admiral

 

Some of the newer big 7200RPM drives benchmark fairly close to the 10K drives with a lot more space for the dollar and less heat.

 

1. i would buy the largest capacity drive in your budget because it doesn't matter how fast it is as your connection will be a bottleneck. it will be nowhere near the speed of your internal drive. don't waste money on high RPM.

2. i paid 20 bux for an 3.5" ext enclosure and 10 bux for a 2.5" external enclosure. 3.5" enclosures require a/c and usually have a built in fan.