I want to lend a vote of support for your project. While I am growing out some decent CX right now, like them just fine, and plan to grow many more in the future, I continue to believe they are unsustainable in the long term. They come from a factory farm system, built for a factory farm production system, and that cannot be sustained indefinitely. Sooner or later, those systems will crash. When they do, it will be nice to find a few birds around that can produce some decent meat and be grown in the back yard.
I personally don't believe a cross is truly necessary, if someone could develop a fast growing meat bird that has decent breast bulk. I think of the broad breasted meat turkeys and wonder why that can't be done with chickens. Those aren't crosses, and can be grown and bred in your back yard if you work at them. And they have a feed conversion rate very close the Cornish Cross.
Best of luck to you, and I hope you succeed. I may be buying some of your birds some day.