Some raid controllers want exactly the same models or they won`t allow raid-0.
Some raid controllers just want same size to do raid-0.
Some will only allow JBOD if there`s any differences in the drives.
Some only allow raid over 2 paired SATA sockets.
Some raid controllers will take 2 drives of any kind and allow u to setup whatever the heck u choose.
Bare in mind tho, whichever drives u choose that are unmatched size wize, the raid will be 2x the lowest size. So if u`r raptor is 74g and the barracuda 200g, u`ll end up with a 2x74g raid.