If your RAID controller has 4 drives associated with it, then yes, you can have one 2 drive array on RAID0 and another 2 drive array in RAID1 on the same controller...unless there is something funky with the RAID controller, there's no reason why it can't be done.
There's certainly one way to find out for sure...
What mobo do you have and what raid controller is on it? Most lower end boards only have support single channel raid for up to four devices. What you need to look for is if your controller support duel channel.