[mark christopher]

your charger is the same as one of mine, the robitronics overloader.
so yes its fine, if your pack is a 4900 then it will automatically set the charge rate at 1C which will be 4.9 amps
trakpowers pack can be charged at up to 2C though no advantage to go that high unless your stuck for time or want to shorten thier life.
if you wantto charge at 5 amps just tell your charger its a 5000mah pack
the balancers are available from most good model shops including MBmodels in leeds