Rocket Launcher:
Normally only has 1 rocket, but you can put an attatchment that increases the rockets to 4 and makes you switch weapons slower.
Possibly Pyro's flareguns (not including the Manmelter cause 3cartoon5me).
Grenade Launcher:
Normally has 4 grenades but can be upgraded to 6 with the proper attatchment.
Possibly Heavy's miniguns.
Engineer's Rescue Ranger.
Medic's Crossbow.
Sniper Rifle:
Kind of very hard thing to do, but if possible, make it so that normally you spawn it without the scope and you can select rear ironsights (Stock SMG's ones)/Bazaar Bargain's red dots/normal scope/Machina scope and any other attatchments from the other sniper rifles, like the mag from the Classic or the Sidney Sleeper's ammo that does very low damage but with very low recoil and the ability to ignite enemies (instead of making them get minicrits).