ReelDeel,
Take a look at TrimBright's. They are LED Underwater lights that mount on your existing Trim Tabs. They run about $800 for all 4 led lights.
The most popular type are HID (High Intensity Discharge), those are usually brighter then LED, but draw a little more power. Those run around $1000/each.
Metal Halide's are the brightest by far, but they are usually 120V/220V and cost over $1500/each.
Whichever type you decide to go with, specially thru-hull, try not to go with the cheapest brand. You don't want to have the cheapest quality thru-hull. The less expensive HIDs will also have ballasts that constantly fail.