Probably help to post a pic of the A/C bracket area. Your car falls into that area where it probably had an Eaton p/s pump.
As far as the water pump, that's an easy one. It will be the C5AE one, aluminum. Date code will be a number like 64 with dots around it. 64 would be the year and the number of dots would indicate the month. For example, 5 dots-May, 10 dots-October.