I'm not much up to speed on current hardware because I'm still stuck with my "old" computer and can't change it before next summer at least. Please forgive me for not going into the details...
First, ATA, IDE and PATA are all different words for (pretty much) the same thing. SATA is the new game in town and there are adaptors that permit connecting one format to the other (foregoing any performance gain though).
The effect of RAID is very dependent on how you use your computer. RAID 0 (Striping) is what you want to go faster. You need two HD and your disk access performance will increase anything from -30% to 100% depending on a few variables. I have been running a couple of HD in RAID 0 (via onboard RAID controller) and it is indeed roughly twice as fast when doing disk-intensive things like uncompressing CD images (all legally obtained, of course

). It does not, cosmically speaking, make a real "feelable" difference in everyday gaming though. Sure, loading levels in HL2 in 10 seconds instead of 20 is cool, but 10 seconds is still at least 9.5 too much and while being faster, that does not really change the experience (your game is still stopped for many long seconds).
RAID 1 or 5 are pretty much for safety purposes and RAID 10 (or 01 or 0+1 or 1+0) is usually not worth it (needs 4 HDs).
I personnally find the Raptors to be quite expensive for what they are. You could buy 2 new 7200 RPM 80GB HD and set them up in RAID 0 (if your motherboard has it or through a RAID PCI card) for pretty much the same price (no, I haven't done the math) and you would end up with comparable performance and much more disk space. Of course, if you're rich, you can always run the Raptors in RAID 0...
There are many articles on the web about the virtues of both RAID and/or the Raptor drives and opinions are very different from one to the other, so you should judge for yourself what they say about the advantages and shortcomings against how you plan to use your system...
Oh, I almost forgot to tell this important detail: RAID 0 is not to be used for sensitive data because if one of your RAID0-ed disks breaks, you CANNOT recover ANY data AT ALL from the surviving disk, i.e. once "bonded" together through RAID0, they can't "live" indepently from each other, meaning you will have lost ALL your data on the RAID 0 array.