i am going to be ordering a lipo and charger soon. i have been looking into what lipo to get. looks like i want at least 5000 mah, 7.4v not sure what "c" rating i need or how many cells. at this time i have the stock brushed slash with the low voltage esc. i want to get a lipo that will work if i decide to go brushless. looks like some lipo combos dont work well with certain batteries? is there such a batter that can be used with the setup i have now and with a brushless setup in the future? also with the charger there seems to be a bunch of different options at $50 or less. i am not sure i need one that will charge more than one battery at a time? do these batts hold a charge for a few days after they are charged?