[BiPolar_Nut]

Case connections like front panel USB/firewire will be fairly standard. Basically the same as hooking the leads for the HD & power LED, reset switch, etc. There will just be wires to hook to pins on the mobo. The mobo manual will tell what goes where, and the case wires should be labeled. Rear panel stuff like sound/network/USB...there's nothing to do, they're just mounted according to the form factor (usually ATX) and are mounted to the motherboard already. They'll just line up w/ the rear panel of the case. As in, an ATX case will line up with an ATX motherboard.

The same form factor standard will take care of cards and slots matching up.

As for power supplies, I like Antec. There are other good ones, too. I'm not claiming Antec is the best, but I've never had any problems with them.

For HD's, I like Maxtors but have had one go bad (out of about 10). A friend of mine has 100's or drives (yes, 100's) and he HATES western digital, but other people havent had nearly the problems out of them that he's had. I personally won't buy a WD, but many people do and don't have problems. I do like their newer raptor drives that are 10kRPM w/ a 16MB cache for performance reasons, but have heard nothing on their reliability yet. I like Hitachi drives, too. It's hard to make a recommendation since they all suck due to cost cutting and poor heat disapation. HD's are a crapshoot and everyone will have different favorites simply due to variance. That's partially why I pick Maxtors since they're usually on the lower end of the price spectrum. I'd go with SATA simply because it's a faster interface than PATA ("regular" IDE). No real need for SCSI unless you're going with hot swappable arrays.

As for on board vs controller card: Pick the best motherboard you can get performance and quality-wise in your price range. If it happens to have onboard RAID-1, cool (will likely be SATA). If not, get a controller card. Some mainboards will claim "RAID capable" but only do RAID-0.

Also, are you planning on booting to the mirrored set or having a single boot drive plus a 2 drive mirror array? If you're booting to it, you will likely need a driver floppy from either the motherboard or the controller card and catch the "Press <F6> to install third party drivers for SCSI, RAID, etc" screen when installing windows...which means you will also need a floppy drive (but you could use your old one and even remove it after windows is installed). I usually don't bother installing floppy drives anymore, as long as there's still one around someplace. If I need one, I'll share the one over the network from a laptop or something (which wouldn't be an option during system installation).