Assume you have to change your primary for 'reasons' so we can list more guns :) He chose well I am making the post for fun.
Sidearm I'd take Glock 20/40 10mm with a red dot and a hot bonded 180-200gr JHP. 6 to 8 extra mags.
For primary, I'd choose probably a Mossberg 590A1 12ga, probably loaded with plated 3in 00, and I would bring a lot more ammo than he did, maybe with the belt and bandolier 120 rounds total.
For the second primary/rifle I'd probably just have a Colt 6920 AR15 loaded with 55gr Controlled Chaos and a 60 rd drum and 6 30rd mags.