You need a compressor. And don’t use an air compressor. It needs to be rated for hazardous material. They typically compress into the vehicle tanks 3,000 psi or greater.
The tanks are the problem but theres allot of research being done on that with steels and carbon fiber. Get the weight down and protect the valve system which seems to be the weakest part. Standardize the tanks and it can be as syple as swapping out you gas grill tank.