Raptor 8MB vs Barracuda 16MB Raid 0

I'm looking for the best bang for the buck solution for the new gaming rig I'm about to build. I am wondering if I'm better off pulling the HDs out of my current rig in my signature & using them. Can I even do this because they're OEM. Is using 2 Barracuda 250GB 16MB cache drives in RAID 0 going to work at least as well as the set up I have in my old rig. I'm trying to keep my HD expenses under $200, but I'll spend up to $300 if it's worth it.

My old rig in my signature will be used by a friend, that is a student, for Autocad and such. If I go with new HDs in my new machine, I'm going to wipe the current HDs & set them up in RAID 1 in my old machine.

What do you guys recommend I do? I need to figure this out before I start ordering stuff, any advise is appreciated.

EDIT: Heres my HD set up in my current machine, it's not showing up in my sig for some reasnon.
2X Western Digital, Raptor, 74GB, 8MB Cache RAID0

If money isn't a problem the new velociraptor will out perform the 2 standard raptors in a raid 0 config by itself. plus you won't have to worry about raid failure. It also runs cooler and quieter.

If you don't wanna spend the money then i'd take the 2 barracudas for you right. the space vs performance trade off will be well worth it as raid 0 doesn't help with frame rates anyway.

The old raptors make good work drives for you friends autocad machine. Since it's mainly doing work the odds of him having to reinstall should be pretty low and the raid 1 would be a good idea.