I'm with AmiSMB, there seems no reason not to use a balancer all the time (if you've got one), it makes sure the cells have equal voltages at full charge, and makes it most likely they will stay close in voltage when discharged.
Balance charging shouldnt be any slower, all they should do is make tiny adjustments to the charge state of one of the cells if its voltage gets slightly above the other.
There are many options, e.g. I use tis one:
http://www.microtechracing.com//prod...at=DISCHARGERS
[Also (while I'm here), I don't quite understand why people would rather take a case-load of (expensive) LiPo's to a meet, rather than alternate a couple of packs, and charge them up inbetween heats - is it a hangover from NiMH usage where battery management was a lot more involved? When I was using NiCd's, and you used a whole pack charge per heat, everyone was charging inbetween heats.]