With standard rear dropout spacing of 135mm, I don't believe you can find a dishless wheel if you plan to use standard drive train (cassette). I believe you can get dishless if you use Rohloff Speedhub or Shimano Nexus internal gear hubs. Another option is to spread the rear dropouts of your frame to 145mm and use a tandem rear wheel. I use a Shimano tandem hub with 48 holes and it is almost dishless. A lengthened chain stay won't affect dish.