Do you have any plans for doing a monthly 3-gun match?
Emperor: obviously you need a shotgun and a rifle in addition to you pistol. Tactical style holster and mag pouches for pistol instead of race versions. You need one or two rifle mag pouches, and you need some sort of shotshell carriers. There are a bunch of different configurations to accommodate different shotgun loading techniques. Probably a good starting point is some 4 shell carriers (e.g. California Competition Works, or similar). Might need slings for both long guns. Tactical Optics division typically allows one optic on the rifle (backup or 45 degree irons are allowed), no optics on shotgun, semi-auto .223 or larger and semi-auto 12ga, 9mm or larger pistol. Consult match rules for more details.
I will delve further! Thank you, Sir.