You may consider using Hydra +1 items in some of those slots, also the versa +1 items are nice.
Anything you would use darksteel on I think versa would be better, I am really bummed because I cannot find any of the Hydra +1 on the AH nor any HQ versa hands or boots. >.<
You may consider using avalons breastplate for MDT instead of the one you have there, Higher percent may free up some other slots idk.
What ever you do do not use earth staff, unless you are just trying to O-shi I need to live macro, if you are trying to tank with these then the Pole arm is nice, if your skill is capped and merited, or... may think about building a custom GK with -PDT taken on it.
Something I came up with for MDT
and for PDT
There is a lot of room there to move things around, I think it comes out to like 44% w/o the pole arm.
Sorry I know I am not a 90 sam as I have been busy trying to get ninja pimped out with my limited play time, and it is my fav job, but I had these sets lying around in my XIAH account and it was something I was trying to accomplish at one point, had to do some updating to current gear, had a lot of it planned out at 75 the last I looked at them.
Edited to get clearer numbers, with those 2 sets you can have near max magic defense, and 40% PT all the time available, or build a 10% GK for max -PDT.
I am wondering what other people would think would go best in the empty slots/ammo (if doing ammo swapping) or in the mdef slots?