If you are gearing Haste/Int make sure you go with Libram of Renewal. It is ilvl 200, obtainable from badges of heroism and unless you go Spellpower, or you are just gearing up and are incredibly low on SP it is the best libram for you. If you are SP (and remember you need 3100-3200 SP unbuffed to support gemming for it) you go with a Arena Libram that gives +sp to FoL deadly, relentless whatever you have access too.
I am on a fairly heavy pop server right now, 2 guilds top 100, 4 guilds anub hm down, about 10-15 looking at 4/5 ToGC. Lots of the mid level guild paladins are wearing the Ilvl 226 or 245 libram to up their gear score. Remember Illumination gives you back 30% of the base cost of HL. If the base cost is 1274, it becomes 1161 with the libram, 1102 with Seal of Wisdom glyph. So 382 mana back on 1102 is like having 34.6% back from Illumination on HL crit, not to mention the fact that we are cutting 172 off the base cost.
Also push as hard as you can for 680ish haste, single best thing you can do to maximize output.