The M785 series is over a year old now, so should be easy to source (on the basis that your countries distributor brings them in) For other hubs; the availability of aftermarket hubs is diminishing every year, as most wheels now are factory builds, other than Shimano, there are option, but they will often be much more expensive, like Chris King, Phil Wood, Hope and others.

For rims, Velocity seem to be well liked, plenty of options as well, like Sun-Ringle, Mavic, DT, H Son, Rigida and others, all depends on your budget.