I don't think you will be able to use any raid other than mirror from Windows on your boot/system drive. That would take 2 out of your available 4 drives and waste space. I personally would go with RAID in your motherboard, as it may also benefit from hardware assistance that it may have.
The main school of thought for not using hardware RAID and instead using the operating system RAID, is that you would be able to take those drives into another computer and import them easily to recover data. Your options would be severely limited for recovery if using other RAID implimentation.