How about this: his room as a haven to escape to for self-calming?
What does he most enjoy doing?
Items that are available that aren't labeled "for autism" but are wonderful.
How about a hammock swing?
Bean bag chair?
Lots of fun sensory items can be found at the dollar store. Play dough, textured balls, good smelling bubbles to blow...
Swim lessons were suggested for my daughter. It encourages both sides of the brain to work together.
How about items that support his special interests?
When I was 7, I'd outgrown traditional rocking horses, but would have loved to have a larger sized one.