You mean raid not rad. Yes you can use 2 Maxtors of identical size and speed. You will need a raid contoller, which can be a pci card or come on board some of the newer mobo's. There are a series of raid configurations that you need to do some research on, I believe your will go with either 0 or 1.
Do a search on "raid" in these here forums and you will have more than enough info.
IMO - there isn't much need for raid in normal computing and a lot of it seems to be hype
LJ