Polar pro case Fits 2 extra and slimmer than the original case
Controller joystick guard You can probably find a cheaper one.
Gimbal guard Extra protection while in the bag.
This is my set up if I'm going outdoor. They don't take up that much space so. You can fit it in any size of backpack you want.
Hydration backack The quality is ok for the price. I dont use the bladder when I have my spark inside.