Fire extinguisher on standby.
With regards to chargers I use an X base 2.0 and it is a great little bit of kit, comes with all the functions you need and all the connectors you need as well. For the price it is a great piece of kit plus comes with it's own power supply and connections for 12v to.
Not sure about the core but looking at it I would think it's probably similar to the Ansmann X base 2 deluxe that dave has. Both are good chargers.
Whatever charger you get I would recommend getting one that balance charges as well to keep your cells in the best condition. One that does storage charging would be beneficial to but not essential.