You are not disciplined enough to stop trading when you are losing too much money and want software that does it for you, but you think a prop firm should let you gamble overnight?
To answer the question, yes firms like Echo and Bright can provide overnight leverage like that, but only if they believe you know what you are doing and have a well diversified and hedged portfolio. A diversified group of equity pairs trading is an example where it can be done, but you will be charged a decent amount on the money you are borrowing.