I am sorry to report that you are bound to be disappointed. It seems from my searches on the Web that the Intel ICH7R chipset that provides "RAID support" on your board is, in fact, FakeRAID, and will be of little or no use to you when running a Linux OS. Intel itself notes on its website that, for 2.6 kernels, the functionality is provided by dmraid. Here is the link: http://www.intel.com/support/chipset.../CS-020663.htm
Fortunately, the all-software RAID support in 2.6 kernels is pretty robust, and should handle your situation straightaway. I have recently been down this path with another chipset that claimed RAID support, and that is where I ended up.
Setting up RAID is described in the Fedora Installation docs, in the chapter on Disk Druid. I ended up defining a separate RAID set for each partition, although I have read recently that you can arrange things to handle several partitions using LVM to aggregate them onto a single RAID set.
Parenthetically, I don't understand how you are going to get any satisfaction out of using a single spindle ("in RAID-0 mode"). RAID-0 is supposed to stripe data onto two or more drives; even if you partition the 80GB device into two logical drives, you will still have a single point of failure, and there will be no speed advantage, because the data will still all have to be written to the single drive. In fact, there might well be a slow-down, because of the need to move the heads a considerable distance to switch between the two partitions for every write or read.