Personally I think the only reason for a co-founder is if you don't have the money to hire someone to do the work you cannot or will not do yourself. Or if you're such a lazy person or so unfocused that you cannot just get the work done yourself without someone else pushing you all the time ... although if this description applies to you then I would suggest that you're not cut-out to be anything other than an employee anyways.
I've been self-employed for almost three decades and I have never missed having a co-founder for anything I've ever done. But I'm highly self-motivated and seldom second-guess my decisions, and with so many years in business I have more than my share of experience doing all kinds of different work -- including programming. So maybe this is why I never missed having a co-founder.
I guess if you want to get funding from Y you'll need a co-founder since PG apparently doesn't fund companies without one -- not many of them anyways. But since you said you don't need the money I cannot for the life of me figure out why you would even want a co-founder ...
Do you really think it's an intelligent move to give away a huge chunk of your future business simply to find a competent programmer???
Regardless of your answer, I think you should hire a programmer instead of trying to partner with one (unless you really don't have as much money as you suggest) ... and there are lots of places to find programmers other than the Bay Area.
I also think you're going to have to get over your fear of someone stealing your idea, and start explaining it in more detail, before you'll find the person or people who will do the programming that makes it a reality. I'm willing to bet that you're not even the first to think of your idea. You might even be surprised when you explain it to learn that other people here already know of similar services, either currently in existence or in the process of being developed.