Spice model for AD8432?

Hi. I am designing an ultrasonic preamplifier based on the AD8432. I would really like to simulate how input noise matching optimizes overall S/N, in the context of the AD8432's active input impedance matching. I am new to using AD's Multisim, and I have a few questions.

1. Does anyone have a spice model for the AD8432, or is there one in the works?

2. If not, is there another part with a similar internal topology that I can use or modify?

3. How would the gain selection pins be handled? I would be happy with separate models for each gain setting, or perhaps a conditional rule in the model. (Actually, I would be happy with anything)

4. Do AD spice models typically include the input pin voltage and current noise sources?