Looking to commission someone for a datapack for an SMP

Hello, I'm part of a content creating group called COA: Center of Attention. 
We are hosting an SMP and have ideas that would have to be implemented through a custom datapack. None of us know how to create a datapack and would like to hire someone to create it for us. We have a budget of a few hundred dollars, we don't know how pricing goes for coding so it will be discussed personally.
The base of what we need is a world generation datapack. 
The world will be split in half, dark and normal from x:0 y:0. 

x would be normal and <x would be dark.
The dark side would be darker, less saturated, foggy, and have particles similar to those in the crimson forest. Hostile mobs can only spawn on the dark side.
The normal side does not have any appearance differences. Hostile mobs do not spawn on the normal side.

That is just the base, there are additional things such as PVP only being enabled on the dark side. But those are not necessary and can be added depending on how the development of the base goes. We will most likely have to come back to you for future work, please keep that in mind.
*see image for visuals