I've been thinking about how much inventory space spell components consume, and I know there are issues with creating a bag to store them in, as I understand it the spells can't see inside the bag to take the components out.
So what I would suggest would be 9 or 10 new inventory equipments slots, 9 of these in slots would be used to put the Spell components from level 1 through 9 in if applicable for your class, and the 10th slot could be used for a Spell Components pouch, the first nine slots would then work similar to the way the Arrow Equipment slot works, and the pouch work like the quiver slot, so if any of the 9 Component slots was empty at a spell casting attempt the slot would be refilled from the bag.
This would allow casters to carry a lot of extra components around without having to sacrifice so many inventory slots for them.