The most "bang for your buck" will most likely be a regular lipo charger and a separate balancer such as a "Blinky" (or comparable). I know the Blinky can be used both during the charging process or after the battery is charged to balance the cells in the battery.

I use a "LipoDapter" running off my Astroflight 110D and plug the Blinky in while it is charging.

The "LipoDapter" is not for everyone. I already had the 110D and didn't want to spend the extra money for a dedicated lipo charger. It is a "work around" that, for me anyway, does the job at a very reasonable cost.