Opinions vary on the lipo thing personally I run one and love it. That controller box you are talking about is a lipo regulator. The down side to lipo is it takes a lipo ready charger which you may not have.
Here are some links to check the stuff out
http://www.losi.com/Products/Feature...rodId=LOSB9820 battery
http://www.losi.com/Products/Feature...rodId=LOSB9608 regulator
http://www.losi.com/Products/Feature...rodId=LOSB9603 charger