I would recommend to buy from a US based company who can at least provide you with some customer service and where you don't have to spend 1/4 or more of the cost of the item to ship it back if there is a problem.
Check out this one from VH as it is similar to the 4B6 you like and will be about $20.00 less with shipping plus you would have it in a few days not weeks.
www.valuehobby.com/power-systems/chargers/gt-power-xdrive-6-4x60-watt-6a-6s-balance-charger.html
These types of chargers will output only what is rated per port or per pack. The 200w or 240w rating is if you were using all 4 ports at their max output simultaneously.