Configurable turrets weight 20 kg extra and take up 1 (body) slot extra.
So...
Clan assault quad: 700 kg
3 ground MP: 160 kg
15 standard armor: 375 kg
APWM Body: 5 kg, 1 slot
Power Pack Body: 25 kg, 1 slot
7-slot configurable turret Body: 120 kg, 2 slots.
615 kg and 7 (turret) slots left fits all your above configurations.