http://www.houseofbalsa.com/store/st...8wTEXE0dM9w4F9
http://www.srbatteries.com/kits.htm

Not knowing what size motor you have, I have attached two of my favorite sites for kits. I have found that SR has the best instructions and quality in a kit. They are little more expensive and their reccommended power systems are a bit dated but the end product is terrific.
House of Balsa has a nice variety of products. Their laser cutting was not as nice as SR and I found thier instructions a bit confusing but in the end I was very satisfied