As long as you are using every GCD you shuoldnt run into to many problems. I have to ask if you read the 969 from maintankadin or heard it explained over ventrilo from a half asleep drunk pally friend ( this is where i heard it first and lemme tell you maintankadin does a much better job) I know that sometimes it really is DPS's fault not the tanks but i think this case there are some empty global CD's. Also because you sain any suggestions
cloak 275 armor
shoulders pvp 30-stam enchant
Glyph of indomitability or black heart. Either is better thna onxyia's trinket keep onys though it has fantastic amounts of avoidance for suarfang.
the vendor 245 helm is a muhc better option for you the second helm is good for an block cap set but, the 245 has more to offer you right now (as it shuold it has more item budget)
Quick somone who tanks as a pally talk to him i am a warrior we only have sheilds in common i can only use that as an IceBreaker