Need External Hard Drive for Notebook

Hi all,
the notebook I plan to get will only have 100 gig 7200 RPM

but I've read thanks to vista I'll only have about 50-60GB to use

So now I'm searching for an external hard drive, I'll be primarily using it to back-up my HDD and later on using it as an external HDD while using applications/games

Is it possible to use an external HDD like that? or would the notebook be slowed down since it has to retreive data from an external HDD?

I have NO idea what a good HDD would be, I've read that brands do sorta matter, and that I could even buy an external enclosure+internal HDD to make my own portable external HDD

my budget for this is ~100-200, anything about 120GB'll do

 

Hitachi is selling a pretty nice kit - I have both a 80 and 100-Gb versions. They're both 7200-rpm and come with a cheapish external enclosure, cable and Apricon (IIRC) boot cd to image the contents of your old HDD. The application has a hokey interface but it works really well. I imaged my 60-Gb M170 hdd (when I had it) onto the 100-Gb drive and it worked perfectly. I haven't ever noticed any slowdown when saving data to an external over a USB 2.0 connection. The drives are a little pricy - I paid $219 at the PX for the 100-Gb.

 

what model is that? I'm looking throug Hitachi's site for kits but can't find it

 

OK Sir - you're in trouble - you forced me to get out of bed and find the box in my closet (its a little after 7AM in Germany and my dv2000 is earning its pay as a lightweight surfer.... ;-). There is no model # on the box but its called the Hitachi Travelstar 2.5" 2-in-1 Notebook PC Upgrade kit - if you Google that string you will find more info on it. Oh the included app is Apricorn EZ Gig II - not Apricon. Sorry - I am a senior citizen!!