I'm not the best when it comes to figuring out builds, so sometimes I try out builds community members put on MarvelHeroes.Info
Often times though I see these awesome detailed build but nothing on the Omega system for the build. I'm not sure if they aren't aware that there is an Omega System they can use and put the link right in the build..
http://marvelheroes.info/builds/omega/
There's also a site that's been around awhile and had an Omega Planner before the one on MHi, but this one has a "search for an Affix" feature that MHi's Omega Planner doesn't have.