I went ahead a took a gander at your Armory profile.
My advise is to get as much rep & crafted gear as you can.(Cloak & boots from Wyrmrest Accord are a good start). While doing that start hitting some heroics and trying to obtain some better gear.
For the record, people around here prefer not to call it "def cap" but rather "def minimum". Which is 535 for heroic bosses and 540 for raid. Most4 of the crafted/rep/heroic gear will put you over 540.
For glyphs, Glyph of Blocking is a must have. After that, it depends on the content your raiding and spec you use. For Naxx, I started with the 15/5/51 DW build, with Blocking, HS & Revenge glyphs.
For addons, I use Tankpoints(helps with gear rating), probably want to use some sort of Raid Frames(like X-Perl or Pitbull, Grid) if your not already. I use one called GoodTargets to tell me if I have aggro or another raider does.
As far as stats, 540 def min as you said already, probably around 22-23k for both hp & armor. You could maybe do less if your healers are fairly well geared.
Hope that helps a bit.