I've got three of the 45GB IBM's. They usually are about $20 more than other brand drives, and I still think it's well worth the extra money, especially when it comes to performace (all reviews i've ever seen always have the IBM drives on top). I got two of them for about $145 and the third I got when they first came out so it was $240 or so. Pricewatch is always a good resource when pricing parts, it will give you a real good idea of what to expect. Although, you can't compare prices on Pricewatch to prices at Fry's since Fry's is a retail store.
Either way, enjoy your new machine!

As for cases, here are a few reviews to check out, various choices depending on how big you wanna go:

ColorCase Yuri/Venus ATX Mid Tower
Supermicro SC750-A Extended ATX Full Tower


And here are a few sites to check out with reviews, and etc:

Reviews / Articles / Overclocking / Info:
Sharky Extreme
Tom's Hardware Guide
AnandTech
Little White Dog
Fast-MHz
Ace's Hardware

Cases / Etc:
Cool Case Mods


This is just a small list. All those sites have links to tons of other sites with great info on just about anything you'd ever want to know (and not want to know).


________
Donato
MkII/Blue/40GB/080000565