Yes, there are 4-wheeled (quad) wheelchairs for full support. You might also consider joining a group for cerebellar hypoplasia critters. CH is what they call CP (cerebral palsy) in critters, and many or most of the cat groups accept puppers too. Some will say that CH MUST be congenital to be CH, but, frankly, I disagree. Brain damage is brain damage, and motor problems are motor problems! One good group is https://www.facebook.com/groups/CHKittyClub/
. I know a UK group, too, if you're interested. There are more cats there, but you should find it helpful.
I agree about hydrotherapy (swimming). I did that some with Baby, who was severely brain damaged. I had to use 2 life jackets on her so they'd fit, as she was a 5 pound permakitten.