Funny that you mention gigging. Just last night, my girlfriend and I were out gigging with a reporter from the local newspaper. Of course, the wind had been blowing yesterday, so, that had the water kinda murky. We didn't see a single flounder, (sometimes it's like that) but we did see about 3 or 4 spot tail bass, and a few other things such as stone crabs and blue crabs moving about, and a good bit of bait fish.
Anyhow, for my gigging light setup, I have a rail design like you mention. (I'll try to remember to get a few pics of it today, and post them on here) Basically, it's 4 pieces of 1 inch x 1/4 aluminum flat bar, with pivot points, with 2 lights on the sides, and one in the center. Because of the way it's designed with flat bar and pivot points, the angle and width is adjustable to fit a wide variety of boats. Each boat may require a different mount, for instance, the War Eagle and the Triton have that internal slot along the inside of the gunwale cap. I have different mounts fabricated for my Triton and my DuraCraft, so I can switch the lights around from boat to boat.
I tried one of the LED deck lights...hoping to cut back on battery power consumption, but, the LED's are horrible, they don't put off as much light as the incandescents, so, I'm probably going to do away with that LED, and go back to an incandescent.
Gigging is sort of a combination of fishing and hunting. In fact, we sometimes use a compound bow, or even a crossbow for gigging, just to add a little more challenge.
Anyhow, here's a few gigging photos, taken about 3 years ago....when we were having some really good nights at it.
Bringing a spot tail bass on board:
A 5 lb 7 oz doormat flounder, taken with a crossbow, in about 6 inches of water:
Another spot tail bass being hauled aboard:
(as you can see, on this night, it was pretty cold outside)
Here's a 7+ pound trout being brought aboard:
(notice my buddy standing there with a landing net, often, when we get a big fish on the gig, or it's not an instant kill-shot, we'll use a net, and scoop the fish into it, so it doesn't thrash and come off the gig....nothing I hate more than a wounded fish getting away)
Here's an 8 pound trout on the scale:
A 7 and a 6.5 pound trout:
And finally, here's a shot of one night's gigging. 6 spot tail bass (the limit is 3 per person in SC) 4 nice trout, and also one black drum:
Well, that's about it. Anyhow, I'll get some pics of my gigging light setup, and post them on here.