I was looking over some autocomplete/lookahead solutions, and I couldn't find anything that could fit well into a React project.
First off, HTML5 has <datalist>, but it's not well supported. Most libraries and polyfills rely on jQuery. I also took a look at some pre-existing React libraries, but they were labeled "Not production ready" and couldn't handle dynamic options.
So, without further ado, here's my cross-browser compatible demo, dynamically updatable autocomplete demo in React: