I've been running Long Hives using standard frames (British National rather than Langstroth, but same principle) for some time now - it's a very sensible solution, imo.
But - it doesn't have to be Top Bars or Frames - there's a 3rd option: "Framed Top Bars" - i.e. solid Top Bars (as per the 'standard' top bar hive, without any gaps between them), with a frame fixed beneath. I made a few dozen of these a while back to fit a 12" deep Long Hive - which then allowed me to run several strands of fishing line across the frame to support the longer comb, and duly posted about this idea on a certain 'Barefoot' site - which went down like the proverbial lead balloon.
But - the bees are loving the larger combs which such frames allow, and the interchangability of these frames with my conventional hives is the only sensible way of running an apiary - imo, of course.
LJ