Surely the only reasonable option.... You completly discount that you can lose far more than your balance with CFD contracts.
If you're in the market with 500 leverage in the event of a significant market event p.e. such as the SNB occasion on Jan 2015 you have destroyed not only your account, you will owe the broker a lot of money, because you will have a hudge unfavorable balance. Forget your stop loss, it won't function in this case.
Forget about garanteed stop loss or adverse balance protection. No critical broker would offer anything at 500:1 Leverage, and if so, he will be bankrupt soon or is anyhow such an extrem bucket shop your money is already gone by the moment you move it on your brokerage account.
Betting with 500:1 leverage is simply plain stupid in every possible aspect and a sure way to lose and get destroyed hard and fast.
There's nothing more to say about it.