Best Paint Preparation & Primer? Aluminum Body

[DMXF]

I'd like to understand what the best process is before having the job started on my car. A prominent painter said that aluminum bodied cars can be susceptible to peeling paint if not done properly. It was mentioned that the body should be sanded with 80-120 grit before prime, but it doesn't look to have been done that agressively by AC originally. Was a primer used that was so good it overcame the need for this sanding? I'd like to use a primer that is white in color as was used by the factory on my car originally. Thanks for any input.