It depends on what you are going to do with it, how good your backups will be, and how much down time you can tolerate should it fail. With your drives, I don't see any reason not to simply do a pair of RAID 1's.  If you want other options, let us know what your plans are with the server.
Dear all, I have PowerEdge R710 with 2x146GB and 3x300GB. I want to install Ubuntu 11.10 server. Which RAID would you recommend for my server? Thanks for your help. Kittisak
PowerEdge R710 and raid