In particular, keep in mind that a project going through Kickstarter now will likely not ship for at least 6 months, if not a year or two. (Some exceptions exist, such as products that have already done the work and just need to scale, but even then they usually take months after funding completes to sort out the logistics.)

So if you can ship within a week or so, long before the project finishes funding, you'll take advantage of the interest.

Your other alternative would be to decide that you care more about seeing the idea succeed than you do about winning by yourself. You could contact the Kickstarter project team, tell them that you've been working on this for six months, and tell them you'd like to join forces to bring a product to market faster. If they're just raising funds and don't already have the details worked out that you have, they'll likely welcome the help, and you might welcome the funding, interest, and marketing.