Linux driver for Intel ICH10R

Can and should are two very different things. Even with software raid where you can use the unused portions of the drives for other tasks I would argue that it's a bad idea.

Performance is the only reason to run RAID0. In a RAID0 the IO operations are stripped across all the drives. Now you want a few of those drives to be doing other things on the side. This additional I/O will slow down these disk and as a result will degrade the performance of the entire RAID0 array.

Usually, the onboard controllers are fakeraid devices, so if you're building a linux server, you'll be better off with software raid (mdX) instead.

afaik if you're planning on a hardware raid solution, you'll need a proper controller, like LSI (or variants - dell PERC/IBM ServeRaid/etc), or 3WARE - all of them are very rare onboard, and pretty expensive.