Shimano Capreo is dead, its almost impossible to find spare parts anymore.

Indeed, the Sunrace solution for small wheels is derived from Capreo but is not Capreo, its better with 10s and 11s cassettes. The 9-36 11s cassette is really nicely spaced and provide a wide range of gear inches (spacing is better than the one of the Ethirteen 9-34 cassette with a slightly wider overal gear inch)..

The problem I see now is that the parts seems also difficult to find, the few online shops I knew who were selling the hub and the cassettes do not have them anymore ???

And its fully proprietary to Sunrace, if Sunrace stop producing the cassettes and/or hub, it won't be possible to replace it by anything from another manufacturer.