If it's an idea you really care about (I wouldn't bother asking what it is coz it's obviously top-secret
) then I suggest you discus it first with people you personally know. If ideas can be stolen in face to face interactions, what more when talking about it with people online going by just their forum usernames. Maybe you can find friends with the right skills?
Since funding the project yourself is out of the question, I suggest going through your network to find willing investors. Of course this would not be easy, if their not familiar with it they might be dubious, if they are familiar enough, you'd have to convince them it's different enough from things they've seen before. Of course make sure you really trust the people you pitch your ideas to.
Now that I've thought about it, do you have good credit record or maybe some available credit line? If your gutsy enough, you might prefer getting the money on your own and using it to pay for the services you need. A problem with asking people for money is that they effectively become your stockholders. Since they got money invested in your project they'd be constantly breathing down your neck. Not every one would be comfortable with that.