Lets start with a few things. I started my druid at the beginning of Wrath (I was 4 bars away from hitting 70 the night when Wrath came out) and was my first real alt I used. Once I got my druid to 80 back in January of last year, I geared her as a bear tank through Naxx. Near the end of Naxx, after I geared out in Bear, I started working on my kitty gear. I stayed kitty spec as my main spec through (SR change was the main reason) Ulduar and ToC. Once ICC came out, I knew finding a group was going to be difficult to find (alts in our guild at the time were not as geared). So I made the decision to go bear spec as my main while gearing up. After getting 4-piece T10 and and the badge waist, I decided to start gearing for kitty.
At this point our guild finally had some geared alts and were moving along in ICC 10 and 25. Up to this point I've been kind of pugging my way into ICC runs, most of which I've tanked. However if I was able to get into the Guild alt 10 man group I would be told to dps (since the 2 tanks in that also tank the ICC 25 alt group). In our ICC 25 alt run, I am asked to help off-tank Marrow and Lady Deathwisper then kitty dps the rest of the instance.
Now here is the issue, I love both bear and kitty spec, but I'm not sure if I should sacrifice my tanking 4 piece for my kitty 4 piece. I have the badges currently to get my 2-piece Kitty right now, however if I spend the 2nd piece on my chest piece I can switch out 2 pieces I use for tanking for kitty. The changes would look something like this:
Tanking
Helm = T10.251 -> T9.245
Shoulder = T10.251 -> T9.245
Belt = Frost belt -> ilvl 245 PVP belt
Kitty
Helm = T9.245 -> T10.251
Shoulder = T9.245 -> T10.51
Chest = Lady Death's Chest -> T10.51
Waist = ilvl 226 Crafted belt -> Frost Belt