I'd go the Cane of Crags, if you were to choose. A Zenith (+1) Relic beats pretty much everything (and even the Allagan one if you don't like losing spell speed).

1 Det is something like 0.5 heals, so you lose 7 DET which is about 3 or 4 cure points?
Piety gives about 7.5 or 8 Mana in return. Using the Cane of Crags will give you 184 or so more MP, which is an extra cure and don't forget increases overall MP so more regeneration.