I have had this problem before and fixed it, but I don't recall how I did it and I did not record it (sadness :( )
I have all the requisite commands installed on OpenSuse to support gparted's efforts in creating any of the supported file systems. I recall that the problem was that gparted could not find the commands, in any event all the file systems are greyed out in the context menu except for the legacy hfs partition which only supports < 2gb. Even extfs2-extfs4 are greyed out.
How do I fix this?