Switches rated for high current *and* high voltage are rather large, of necessity. You can find them on Mouser, Digikey, Farnell, etc., though it will take a little while to poke thru the listings.
As long as you are NEVER switching under any load, you can use one of the breakers like I use from an old powerchair (28-29v max system). It's capable of 83A IIRC, before it would pop as a breaker. The on my trike's 14s (58v full) pack doesn't get used as a switch often, but I used one just like it multiple times a day for years on CrazyBike2 with the same voltage.
This is what I'm using; it's in a different spot now, but works the same:
They are a bit on hte large side, but I also have pulled over 100A for seconds thru them, and peaks of a couple hundred amps for a second or less during certain testing:
You can also use the battery cutoffs like Harbor Freight and other places sell, to switch a battery in a car, boat, RV, etc. off. I'm using one of those on the trike to switch the system off multiple times a day, for years. Again, no switching under load. Better than a switch, because without the "key" you can't turn it on.
Most people (even thieves) probably don't carry one of those around with them.
it's in a different place now, but this is the one I'm using:
The problem is only if you use it as a breaker (switching while current is flowing at a high enough rate), at a voltage higher than it's rated for. That can allow the current to continue flowing *even though the switch is open*, causing an arc across the contacts, which is basically the same as a welding arc, and can thus heat it fast enough and hot enough to cause a fire.
Not a problem as long as you're only switching when current isn't flowing.
The stuff made for solar or marine use will likely be more robust than that for automotive uses, but also probably more expensive. Probably worth it. My breakers are just salvaged from old powerchairs (as are most of my Anderson connectors and heavy gauge wiring), and they work fine so far...but they're not used as breakers.
