DT
Yes the SAP/SAR3 is a 2 pack zinc chromate primer, it's the basic yellow one for steel. They do a thicker green one for single coating alu.
But for the sake of your life. when using and 2 pack paints (ie base and isocianate hardner) you MUST wear a full face air fed mask. These are paints are lethal and for proffesional use.
As for Trimite paints. They are on the MOD spec for various systems (def stans) although there are also others, at least when I was involved. But for true corrosion protection I would never rely on anything your local car paint retailer would offer.