I don't know about your winch at all, but I have a hank of 3/8ths amsteel that I bought for one of my winches. 19,000lb breaking strength, it is small and light, yet not so small that it will hurt your hands if you yank on it.
It's kinda pricey.
Generally, you replace whatever steel cable you have with the same size amsteel. Call the local bandit dealer, they will tell you.