Yes, the various airline websites (ANA, Aeroplan, UA) as well as Expertflyer tend to be the best options if you want to search segment by segment (possibly including "easy" connections)

As mentioned above, there are dozens of award booking services out there incl. myself and a few other FTers. Some are better than others...most are travel bloggers, a few just turned their knowledge into a (side) business and a few are travel consultants who also operate an award booking service.

You can find a fairly comprehensive list here.