switch mode voltage regulation chip

I could do this design from scratch, but would like to keep the parts count
and complexity down.
I'm looking for a chip to build a voltage regulator around. It's for an old
six-volt vehicle. The battery in this vehicle undergoes wide changes in
temperature, and I want the regulator's setpoint to vary with temperature to
compensate. So I'd like a chip that either
A) has an internal voltage reference with a negative temperature coefficient
that corresponds to the temperature profile for lead-acid battery charging,
or
B) has pinouts for both error amp inputs, in which case I would build a
distinct voltage reference with appropriate tempco.

This is a negative ground vehicle, and the generator field switches on the
low side. On this vehicle turning the key off doesn't cut power to the
voltage regulator. The vehicle has no starter motor, radio or heater blower
to run - just the igntion, headlamp and taillight, so it uses a very small
battery. Therefore a chip that has a low quiescent current draw in order
not to run down the battery when parked would be ideal. I don't want
something that pulls 5 or 10 milliamps from the battery all the time. 100uA
or less would be nice. Of course there will by necessity be a rectifier at
the generator output, so there is also the possibility of taking power for
the chip from the anode end of the rectifier, if it would work.
I spent some time on digikey's parametric search and my eyes glazed over
after a while. Maybe somebody here can suggest something.


Those wide swings in temp are the problem, put the battery in a cool