The Supa Dupa weapons are hidden in various missions as noted below.

Weapon	How to unlock
Supa Dupa Bullet Proofa Vest	In Mission 12, Phase 4 it can be found after boarding the helicopter and flying to the northeast corner behind a snowman.
Supa Dupa Missile Boosta	In Mission 8, Phase 3 it can be found behind a bush in the southeast corner of the map.
Supa Dupa Rank Boosta	In Mission 16, Phase 2 it can be found in the northwest corner. It looks like a sign with four stars on it.
Supa Dupa Troopa Boosta	In Mission 20, Phase 1 it can be found in the center of the map. It looks like a big yellow S.
Supa Dupa Troopa Boosta (2)	In Mission 22, Phase 2 it can be found in the southeast corner behind a turrent.