All of the kits look great, except that dealextreme.com is not listed under official arduino distributor list. It infers nothing on their quality but legitimacy in using the word Arduino, which is a trade mark. All their Arduino boards say arduino but I doubt they are official distributor for the arduino team. It's more of a moral decision whether to buy from then than a technical one 
I bought one arduino that is copied but it removed the word arduino, which is all that is need to be out of arduino team's way.