Help in Hard Drive Choices

Hi,
First I would like to thank all you guys for your help in my recent posts! As some of you know, I am currently building a workstation for video editing. I am basically building a system very close to the specs of Mike Kujbida & John Rofrano. "A special thanks to you two"
I have a few questions in regards to what would be the best choices in hard drives. As of right now the drive configurations are as follows;

Drive 1: Seagate 146GB SAS Cheetah 15,000rpm
Drive 2 & 3: WD (2 x 500GB) WD5001ABYS SATA2 7,200RPM
Raid 0 configuration.

I am considering changing drives 2 & 3 to either 10,000 or 15,000 rpm drives. I have a few questions for you experienced guys that are in the know;
1) Normally the configuration for drives 2 & 3 would be used in Raid 0 as shown. If I was to go with 10,000 or 15,000 rpm hard drives, would I be able to run them in a Raid 0 configuration? Maybe I wouldn't want to.

2) Would I be better off with the higher rpm drives as separate drives? If so, how would you use each drive in Vegas pro 8 and DVD Architect?

Since I am currently putting together a new system, I want to make the right choices. I value all of your opinions and suggestions. Below is what I have configured so far with the exception of two monitors. I am currently trying to find a good OS LCD 22" or 24" monitor and a good LCD TV for video/editing. As always thanks for you advise and help. Ray

OS: MICROSOFT Windows XP Professional w/SP2
Case: ANTEC SONATA III 500 (black) ATX Case w/extra120mm fan
Power Supply: Cooler Master Real Power Pro 750 watt ATX 12v
Motherboard: INTEL DX48BT2 Core 2 Extreme Processor
CPU: INTEL CORE 2 QUAD Q6700 2.66G (1066Mhz)
CPU Cooling: ZALMAN CNPS9700 NT copper base cpu cooling fan
Memory: 4GB (2 of the following kits needed)
CRUCIAL ballistix BL2KIT12864BA1608 2gb kit (1gb x 2) match pair 1600mhz
OS Hard Drive 1: SEAGATE 146gb ST3146855ss 3gbit SATA scsi 15000rpm 8mb
Hard drives 2 & 3: WD (2 x 500GB) WD5001ABYS SATA2 RAID 0 7200RPM 16mb
DVD Writer/Burner: PLEXTOR px-810sa 18x DVD+/-rw dual layer/dvd-ram SATA internal
Graphics Card: Nvidia Quadro FX3700 512mb pci express 2.0 dual dvi/tv-out
Sound Card: Creative Labs Sound Blaster x-fi extreme audio 7.1 24-bit pci express
TV Tuner: Diamond TV Wonder HD600 pci express tv tuner
Networking Card: ZONET ZEW1602 802.11g 54mbps wireless pci desktop network adapter card