I am buying a Larrivee, one of the Rosewood models. Do I opt for the built-in mic w/equalizer (for gigging) or not? If not, what pickups are recommended?

I have a feeling about what the answer is going to be...

I'd say get it without and then experiment with pickups before getting one fitted. I've got a short necked Martin with a slotted headstock and I looked around at tons of pickups and ended up with the most basic Fishman clip-it-in-the-soundhole thing you can buy. It was about $70 or so equivalent. That and a Boss EQ pedal and you're laughing. sounds great.

How much extra for the built-in mic?

I have a Fishman magnetic pickup (Rare Earth Single Coil).

I hate the sound of Piezos usually.