Silicon-based lifeforms are fun to think about, but if we find extraterrestrial life I guarantee it'll be carbon-based. The bonds between silicon are so weak, so easily broken, while carbon is insanely stable. It's bonds are strong in comparison.
Though, with how fast the Universe, spacetime, is expanding, it is likely we will only find other life within our solar system. Or we make a generation starship. But if we did that, then I imagine tech would progress to the point that by the time the first generation starship arrives at it's destination, newer ships will have already arrived.
/enddrunkrambling