Starting with the shotgun is a good option ... but I am partial to ending with the shotgun. With a 97, I would not have to worry about a hull in the shotgun when I discard it to shoot another gun. I have not had a hull stick in my shotgun for a while (knock on wood) but it used to happen more frequently so I got paranoid.
I pretty much always shoot my long guns back to back since the transition is smoother. The default starting position puts my hands right there by my pistols, so, long story short, I'd probably shoot it pistols, rifle, shotgun.
This plan would be reinforced if there were a complex pistols sequence to remember (I'm thinking of you, Badger Sweep) so I could do it while fresh in my mind.
AM