As usual, I agree with tmcase.

And with Kent!
I haven't used the u, I don't think it's very popular in the States. For starters, it's an eGo clone, so we have no idea how good it is. Some eGo clones/knockoffs are very good, especially those made by SmokTech and Vision, but this manufacturer is a complete unknown--at least to me. It may be a good battery, but we just can't be sure. Second, those batteries don't offer variable voltage, which is a very useful feature. So I second tmcase's recommendation to get an eGo-C Twist or Vision Spinner (the latter if your eyes are not what they used to be--the voltage markings on the Twists are almost impossible to decipher).
With regard to C4 clearomizers that come with the kit, they don't have changeable coils (CC or BCC) and I wouldn't bother with that design. CC/BCC is a very practical feature and makes maintenance a breeze. If you like clearomizers, I suggest getting one of the newer ones that come with changeable coils, like Kanger T2 or Vision mini ViVi Nova (top changeable coil); or T3, baby T3, eVod or Tabac BCC (bottom changeable coil).
I recommend the kit from MyVaporStore--it has everything we've recommended above, lets you customize your selection and comes from an American vendor:
http://www.myvaporstore.com/Vision_Spinner_Joye_Ego_C_Twist_Combo_p/vvs-c.htm
Good luck and happy vaping.