A paladin needs neither strenght or intelligence.

If you want optimal tanking (read: max control) go for +defense, stamina, block that kinda thing.

If you want optimal threat, go for +spelldmg gear in addition to +defense, sta, dodge etc. +spelldmg items usable for tanking are few and far between, even after Outland, but your mainhand weapon should be a caster weapon, as opposed to a dps weapon.