I have a couple California Competition holders, which seem about as good as any. I'm not convinced moon clips are the best approach for CCW and speed loading, without some accommodations.
Commercial SD ammunition has a swaged rather than rolled crimp, which leaves sharp edges to catch on the cylinder. Hand loaded cartridges load easily, without fiddling. However hand loaded cartridges may not be the best choice for self defense.
A reasonable alternative is a loading strip, which are available for 8 rounds of .38/.357. It's not quite as fast as a speed loader, but generally faster than a moon clip, and a lot easier to carry concealed. I haven't seen an 8 round speed loader for the N-frame Smith.