Sponaneous Domain Casting: Interesting character options?

[pabelfly]

Following up on this, what would be a good 1-level arcane casting dip that wouldn't effectively be a dead level? I'm thinking Sorcerer, learning only spells without Somatic (there are some OK options), and maybe one of the Sorcerer ACFs that give a martial weapon proficiency.

I'd go Sorcerer with Dragonblood Sorcerer ACF (you need a dragonblooded race for this). This will give you Draconic Heritage as a bonus feat. With that, take Draconic Aura (Cold) feat and get a scaling +1 to +4 bonus to your spell DC for Cold spells.