Saw a thread somewhere on this subject. If quality is what you want, and cost isn't an object, look into Amphenol, Bendix mil-spec/ type bulkhead connectors, if you need multiple connections. I think Deutsch connectors might have something as well, but less expensive.
I just drilled a hole in the space between the rear upper hatch and body on my LX450 and installed a grommet for a LED light bar I mounted on the rear spoiler.
I just ordered lights for my new rack in picking up for my new 80. I'm using the Heyco version of above. They also make an aluminum one that sees a bit more substantial and less likely to deteriorate.
I've got the same issue - need a pair of floods mounted to the rear of my pickup topper and trying to find some good quality glands that won't leak , not easy and a lot of imported copies that aren't worth buying .
Sarge