How about we allow all weapons, but picking extra weapons will cost you HP.
There will be a HP cost associated with all over-powered weapons. When you spawn to duel, the overall cost is deducted from your HP.
Example:
M60, M4 - 30 HP
Ruger 20 HP
Chainsaw - 50 HP
Molotovs - 60 HP.
....etc.
No miniguns and RPG ofc