"Stinger" is a brand. They sell relays among other things.
First of all, on a good day, most of the rocker switches are rated at 20 amps, but I wouldn't put much more than half of that (10 amps) through them. The good news it that the right size relay can act as a heavy duty switch, so that's what many people do for their "key-on switched fuse buss" and also for things that have a particularly high current draw, such as a big light bar or a loud horn.
The Stinger relay, or similar relay of say 50 to 100 amp capacity (continuous), is used to power a "key-on" fuse block. One side of the relay coil is connected to ground, the other side of the relay coil can be connected to a key-on positive, such as Aux fuse #5 (I made this connection under the factory fuse block on my 1000-5 SE). This is one option that will power up the fuse block when you turn the key on. There is another option if you have already installed a "key-on switched ground relay", this is often used with the True battery isolator to switch ground for the dual voltmeter (this, so the meter isn't on all the time). You can use that switched ground to drive the "Stinger" relay and connect the other side of the relay coil to a continuous positive.
A separate relay, such as a common Bosch 35 amp automotive relay (they are cheap) should be used for a big light bar, such as you are using. You can provide the positive for this from a fuse in your key-switched fuse block. Your dash switch will only be providing switched positive for this relay coil, thus only low current goes through the switch and you don't have a jumble of heavy wiring going to switches that way as well.
