6gb should be fine, what Vista install did you use, ghosted a old copy onto new drives? doing that can screw up allignment though I'm not 100% sure how to check, I'd read into the ocz guides if you think performance isn't where it should be.
For raid array setting up you don't need drivers, the raid array itself simply reads each drive as normal single drives, windows needs drivers later to translate what the southbridge is telling it, basically masking the two drives as one. But vista/win 7 should have fairly appropriate drivers for it already though not the most up to date.
Its worth going with the latest motherboard bios(if yours is semi old) as newer bios's get occasional raid bios updates aswell, which the way things are going should be looking to fix problems with ssd's as they get more common. Likewise newest chipset drivers could help aswell.
Just smegging around with vlite at the moment, apparently can take a while to rebuild a iso, guess we'll see as its doing it now. Removed tonnes of stuff, no idea how big a difference to the install it will make, smaller iso, easily but install I'm not sure. But removed some stuff like defragger, loads of drivers and some other stuff, disabled a lot of the things that "track" what you do, error reporting, search indexing and a couple other things to help minimise writes.
Will burn that and hope it installs ok, though being a pain the "new" windows 7 build turned up with a few fixes I really wanted in the way the UI works aswell as shed loads of bug fixes and better app compatibility so I'm torn between which to use as Windows 7 seems to by default install a much more streamlined version of itself than Vista. bad timing
Waiting on the memory to turn up aswell, according to DHL its out for delivery still but its getting a touch late in the day.
Do'h, I just realised, maybe I should be whacking them in not as OS but as backup on current install and test them from there, that way changing the allignment/stripe and testing single vs raid shouldn't be too much of an issue. Not sure if I can be assed tbh, though without testing not really sure what offset to choose.