On 02/06/2015 09:35 AM, Jon Elson wrote:
  These things are NOT cheap, but I'm expecting to
get better life than most
 of the commercial units, which I think have crummy thermal design. I think
 they work out well. 
Commercial drop-in replacements have been available for some time.  E.g.
http://www.amazon.com/LEDwholesalers-Brightest-Fluorescent-Replacement-Appr…
Not a bad price (comparatively)  either.
--Chuck