Unfortuantley your 24" in height is your downfall and the reason you cant do this unless you are extremey skilled is LST.

I too have 24" wide X 18" deep.

I have more height so that is the only difference.....but its a DIFFERENCE that will prohibit your plans from success.

you cannot grow two plants that will veg then flower...just not enuff height.

Here is what i can do with the space but not if i only had 2 feet of height to work with.