Rifton Bicycle for Adam

Adam was born with many issues and one was having a stroke while in utero which affected the majority of the left side of his brain ( which controls his talking and walking abilities). Adam also has Down Syndrome, Autism, Epilepsy, Celebral Palsy, Neutropenia. Recently, the school has a special needs bike they used in helping him get those legs moving and it would be great if we could get one for home. The bicycle the school uses isn't just used on Adam therefore isn't always available for his therapy time.  Attached is a video of the school bicycle used. 
This bicycle should last him a few years because it is  adjustable.
As many of you know, Adam isn't getting any lighter and the NEED for him to start walking is getting greater each day.
Any help is greatly appreciated