Whelen is extremely high quality stuff. I have a friend that works there and I got the tour of the facility and it is very impressive. And everything they make is 100% made in the usa. They even make their own circuit boards. All of the fd pd and dot around me have all whelen stuff.
I went with those. I bought mine awhile ago with six strobes instead of four. Has worked real well for me and they kick on every time with no problems. I mounted my control box under the back seat and the supplied cables were not long enough to run it all the way to the back tail lights (99 extended cab)... just a heads up.