Recommendation for first/best SumoBot kit

I would like to build my first SumoBot, but I'm not confident enough I can design and build one from scratch. Can you recommend a good kit?

When I was about nine I used a lego Mindstorm kit(http://www.amazon.com/LEGO-4544091-Mindstorms-NXT-2-0/dp/B001USHRYI) to build a SumoBot.
It worked pretty well.
Jaredpi