As you can see I have over the un-critable mark over 540 with 556 def and have about 25k life unbuffed with 22k armor. I am working on getting more epics but I have never had a 'tier' item before (i was always dealing with gladiator, merciless, vengeful, brutal in pvp) and am not really sure where or how to get them.
I have begun doing a little naxx as an off-tank and will see where that goes but any other suggestions on gear, gems, enchants, dungeons would be appreciated for where I should go from here.
EDIT: I currently am using the tabbard to be Argent Champion to get revered and get the helm enchant since I finished getting revered with wyrmrest
Check out the gear lists on the forum. Keep running heroics - you've got a couple of really tasty pieces out of them so far, but there's a few more to get. Other than that, just raid - Naxx, Sarth, hit Archavon if you've got time.
More to the point, certain bosses drop "tokens" for T7 armor. Each token is good for 3 or 4 classes. Say, if you down 10-man Sartharion, he'll drop a token for gloves; someone from the appropriate class can take that token and trade it for one of the pieces of T7 appropriate to that class (most have two choices).
Archavon just drops random great stuff. Can be two pieces of Hateful arena gear, can be T7 (not tokens, just the gear). Keep in mind that T7 and arena gear is class-restricted, so if something drops off Archavon and you don't have any of that class in your raid, nobody will be able to use it. On top of that, because both Arena gear and T7 are technically "vendor epics" (bought either with arena points or a token), they can't be disenchanted, so, er... no shard or crystal or whatever stuff turns into these days. (Hey, our guild is a long way from disenchanting epics! ;p)
The token system is good because it means the likelihood of someone in your raid getting a nice piece of gear goes up significantly. Rather than having, say, druid-healing shoulders drop, and your raid has no druids (or one druid, who got the shoulders on his first run, and you've already disenchanted 15 more of them), you're much more likely to have someone in a three-class-band who needs the item, and even if they all have it, one of them can take the token and get an off-spec piece of epic armor.
Downside is that there's a bit less loot diversity than there once was - most bosses in modern Naxx have significantly fewer drop possibilities compared to a Kara boss, excluding the one who can randomly drop -any- Naxx loot...