I have a Polaris horn. I like it. 70 bucks? Nice button with a horn picture. Wired hot all of the time in case somebody is getting ready to back over me while parked which is the number one reason for a horn IMO. I put the horn under the front hood cover inside of the box.
I have a dome light and a cargo light that I like a lot, made by Rigid? Those lights are a little pricey, but well made. The curvature fits the roll bar. If you buy those, drill one hole, then hold it up there for a guide to drill the other one. My cargo light is a little crooked. Still bugs me. The link is in my build thread.