After you boot from your vista DVD, and enter in your key, select "Drive Options" (Or something along those lines) and then select "NEW" and it should give you a option to split partitions, just enter in the amount of data that you want on the other partition.
If vista is detecting the partiton than you shouldn't need drivers.

Most motherboards already have the raid drivers built-in to vista.
Sadly, to redo the partitons its gonna be easier to just reformat again and set up the partitons directly after entering your key in.
CPU Q6600 (3.4GHz - G0 Stepping) |
Motherboard Asus Rampage Formula |
Memory 4GB G.Skill (DDR2 1014) |
Graphics Card VisionTek 4870X2 |
Hard Drive 2x 150GB WD Raptors (Raid 0), 500GB WD Caviar SE16 |
Sound Card X-Fi Fatal1ty FPS |
Power Supply 1000W Ultra X3 |
Case Thermaltake Armor |
CPU cooling Xigmatek HDT-S1283 |
OS Windows Vista Ultimate x64 |
Monitor 24" Samsung 244T |