I don't know anything about CAD programs, and hope someone more attuned to it can provide more specific advice.
More generally, I would mention a few things which might be relevant (although you prob are aware of them anyway).
You must use NTFS.
It sounds a good idea to have the CAD program on the Raptors Raid 0 setup, and Windows on the Maxtor.
You have 2GB of RAM, which by normal standards is huge, but I have no idea what amount of memory is demanded by your CAD program and to what extent the pagefile will be used. w2k pro by default sets your pagefile size to 1.5 times your RAM as the minimum and 3 times your RAM as maximum (with an overall max of 4GB, although you can create multiple pagefiles). With 2 GB of RAM already, I wouldn't make it too large. Try it out, and while using your CAD program, use Task Manager to see what sort of memory is being used to give yourself an idea.
Whatever size you decide on for your pagefile, in w2k pro, I would set both the initial and maximum amounts for the page file to be the same, giving it a fixed size. With other computer uses it may not make much difference, but with such memory intensive prog such as CAD, you don't want Windows to waste time expanding the pagefile as and when it is necessary. It also reduces fragmentation of the drive.
Although the conventional wisdom is to have the pagefile on a drive other than where Windows is running, there is really an underlying assumption that the other drive is less frequently accessed than the Windows drive (which normally is the case). With the CAD program on the Raptors (and possibly the destination of the CAD work files being on the Raptors as well), having the pagefile on the Raptors (even on its own partition) reduces the intended benefit, although it does have the advantage of being on a faster drive (because of Raid 0).
If you do decide to have a dedicated partition on the Raptors for the pagefile, (1) I would still keep at least a small pagefile on the Maxtor for OS use. At least that is Microsoft's recommendation, and acc to them, W2k is supposed to be able to select which is the better pagefile to use. (2) Remember to set the dedicated partition size larger than the actual pagefile size, otherwise you might get an error message saying partition is full or something. Give it at least 10% more.
Another consideration is the Temp folder (or whatever temporary folder which your prog uses to store temporary files). I assume that CAD programmes need a large temporary folder to run and writes fast and furiously to it. So you want the temp folder on your largest and fastest drive, presumably your Raid 0 setup. Change the user variables TEMP and TMP from the default C:\Documents and Settings\Username\Local Settings\Temp to your Raid 0 drives, say X:\Temp. Change those values for the System variables as well.
A little sidetracking from your question, I would also clear out the Temp folder regularly and defrag regularly.