Hmmmmmm, well, it depends. If you go the first build will you be going with DMM? Defenses are nice, I'll give it that.
As for the second, if you go that way you'd definetely be the primary spellcaster, and as such would we need me as a secondary arcane?
If you go the first build, I'd definetely end up going blue mage and be secondary caster, especially since Blue Mages can learn divine spells, though they still cast them as arcane. If you go the second build I'd end up being primary divine and not sure what I'd do.
Both builds have their merits.