Maxtor got bought by Seagate I believe, so that could explain the deal. I've had good results with their drives in the past. You can get a case for like $30-50 for the internal if you want the ability to change drives later and if you want to save a few bucks. I personally prefer to just pay a little extra and get them preassembled. The price looks to be pretty good. You can get a LaCie 250 with a triple interface for $160, so for a couple extra bucks you can get another 50 gb. http://www.macmall.com/macmall/shop/detail~dpno~605771~name~250GB+Extreme+Triple+Interface+External+Hard+Drive~mfg~300790U.asp You may be able to do some more shopping around and find a cheaper model though.
I bought the OneTouch III, 300GB FW/usb 2.0 for $149 a few weeks ago at (only because of the price) BestBuy. I like the drive as it's quiet and fast not to mention it was all there, just plug it in and format Try looking around for the OneTouch III for the same price or close to it. Still 300GB is nice for all your storage needs
I've got the drive you're going to buy - it's very nice.
I'd be cautious about buying a case separately and putting in a harddrive, unless you've already seen the case in action - i bought just a case to house an 80Gb drive, and it is the noisiest most c*$p piece of cheap s#$t you ever saw - even though it was the "better" of the ones available..
So only buy an ext case if someone can recommend a specific one (or you might end up with a lawn mower like i've got! You really appreciate the finish of the maxtors from my experience. Note: i've not used the LaCie's or anything, so i'm not saying they're better or worse. But if the price is good... Hell yeah.)