My general rule is to replace the weakest pieces first, where at all possible. In my case, I walked into ICC with an i219 cloak. So that went first. My belt was a 226, so that went the other day. From here, I'm a little less certain, though the Stam trinket is mighty tempting and would have the greater effect on my survivability than the armor. So that will likely be next.
Look at your gear from that perspective, and check what drops may also be available for the content you're able to clear. From there, creating a priority list should be straightforward.
Thanks for the advice. I was thinking along the same line. My 232 belt is the weakest, though it has slightly more avoidance than the frost belt. However, ever other stat on the belt is better and more slot. hmm...I think I have decided to go with belt.
The belt is what I got first (just got it last night). That belt has 20 base stamina more than the one you have, higher defense and parry, and although you lose dodge, you do gain two additional sockets.