Boburk,
I'm completely fine with your way, simpler is ALWAYS better. Can you mount and share your results? How high above the water and how will you orient the lights compared to the post?
There will probably be some 'magic' distance above the water where the bugs are more likely to hit the water and stick rather than flitting out the light and flying away?
If I can get by without the fan motor and flail to knock them in I'm all for it.
I would also ask you to experiment with light color. I see from reviews on amazon that these are more the cool white light, no Kelvin scale rating is listed. That may work great, or you may have to color the lens or add a colored filter to get different hues.
The 2 intensity switch option will be handy to extend your run time if you don't need full power at night.
I do like the idea of not running an a/c cord out over the water
