I see this question dropping down without any responses. My guess is that you haven't really given enough information for anyone to figure out what you're trying to accomplish with whatever size plane you might have.

So I'll toss something in anyhow. I'll use a 4-40 rod threaded on one end with a threaded clevis. I'll cut it to length and solder on a solderable clevis on the other end.

But no one knows if you're trying to save weight (you are in the 3D forum afterall) or going for strength or whatever. I can't really comment on the ball links idea. There's a limitless number of responses you could get here and I couldn't say if what I do is right for you (but for sticking with metal gear it's kind of light and simple). I'd try to post again with more specifics.

Good luck