Autism moms or specialists

I am a personal care assistant and my client is an autistic adult and he always takes his clothes off and sometimes won’t put them back on. His mom has had a lot of trouble finding those jumpers or body suits for autistic adults that he wouldn’t be able to take off himself. Problem is he is a 3 or 4 xl so even when looking online I’m not able to find his size. Anyone have suggestions or experiences with this? Is their something else that might work instead? This is a constant issue for her everyday and would help a lot