Hello, I am glad you joined a forum. I have done a lot of work with and own Savannah Monitors.
First of all on your list, please do not purchase any aquarium type tanks, This will only further your Monitors languishing, This animal needs to be caged in a minimum 8 foot wide, 4 feet tall, 4 feet front to back tightly sealed enclosure that can hold about 18 inches to 24 inches of soil that will hold a burrow.
Savannah Monitors live down in holes like a woodchuck does, this is how they conserve humidity and prevent dehydration.
I have prepared some informational web sites with a lot of input from Daniel Bennett (A field biologist who has studied them in the wild) and You will find a lot of what you need right in there.
Hopefully, it is not already too late, as deep dehydration alters blood chemistry and leads to internal organ failure.
I just hope you are ready to take on the responsibility you just inherited, because proper maintenance of any varanid is not cheap or easy.
However the good news is, once you have the environment up to par, they are wonderful healers, Daniel found a wild Sav in Africa that had lost it's entire tail, and healed without any medicine.
Good luck, and stick around, I'd love nothing more than help you turn this into a success story for us all.
The links and pictures will follow in my next post..