Other than myself, there are a number of brokers I know at various houses that I would trust with a friend or a family member's account. I have directed accounts toward them often in the past. They all have different areas of expertise so it would depend on your style of trading and what markets you plan to be involved in. They would all be happy to speak with you, and it would give you a number of additional choices.
I recommend that you speak to several before making your selection.
Costs could be as low as $2 per round turn trade or possibly a few cents lower, but it will depend on the amount of service and assistance you require, and the size of the account and the volume of your trading. I have clients who pay me as much as $45 a round turn, but they expect quite a lot of service for that rate.
As always: Trading in futures and options is very high risk investing. You can lose all or more of the money you invest. Only risk capital should be used.