Help me pick an amulet? :)
Here you go http://wiki.guildwars2.com/wiki/List_of_ascended_equipment#Amulets
If you want toughness and vitality then go with the soldiers amulets which are the third ones down.
Live life to express, not to impress.
Don’t strive to make your presence noticed, just make your absence felt. ~ unknown
Not sure what build u are going for but u can try cleric ascended gear as well if u wan some healing power.
Just for your info, guardians prefer to stack toughness rather than vitality as regardless of the amount of vitality we have, we heal for the same amount.
As an example to illustrate my point, assume u have 300 hp regen from virtue of resolve passive.(with cleric gear and absolute resolution, u can definitely reach it)
If u have 2.7k armour, u take 1000 damage. it takes 3.3s to recover from the hp loss.
But if u go for vitality , u will take more damage like 1300 damage, it takes 4.3s to recover from the hp loss.
Thats not to say that vitality is useless, but i will recommend you not to focus on vitality too much(16~17k hp) and instead get some other stats to complement your build like precision.
So my recommendation is to get some knights(tou/pow/prec) and mix it with some soldier gear for more survivability. Or get cleric gear(heal/pow/tou) and soldier if u really want to be a tank.