Hi Vincent,
I would follow Kim's excellent advice. I took his advice last year and I am very happy I did. The TP charger, along with the TP large balancer, is perfect for our needs. I use them to charge two of my 14.8V (4 cell) 4,200 mAh ECL batteries at a time. This charger has a data port (feed back loop) that will shut down everything if there is any problem with any cell. A great safety feature.
FWIW: an extra charger can save us $$$ by increasing our flying time at the field. It is much cheaper than doubling the # of batteries. I also have a Multiplex charger (about $100). This added to the TP unit allows me to charge three batteries at a time. With six batteries this allows me to fly as long as my old reflexes can keep it up. BTW, the Multiplex charger is also an excellent unit. I have used it for over 3 years. Used with a balancer it does a very good job with our ECL systems.
Like the others have said, you do not need to monitor your batteries too closely if you are using good charging equipment. The metal box Kim mentioned will work well. I use rectangular ceramic pots from Home Depot to cover the batteries during charge. I also highly recommend placing the batteries on a piece of tile during charging.
I have only had one LiPo mishap. It was a few years ago. It was with one of my smaller, 11.1V E-R/C plane batteries. It was with another brand of charger that blew the battery shortly after it was plugged in. Pieces and ashes where spread all over my shop, with a lot of foul smelling smoke. The remains of the battery welded itself to the tile. BTW: tile melts at around 2,000 degrees. I now cover all my batteries and make sure they are on tile while charging. I have never had any problems with my Thunder Power, or Multiplex chargers, but I will still try to be careful.
For a power supply I use the Radio Shack 12V, 24 Amp switching power supply. I think it is around $85? It is light, small, quiet, and has a fan. This can run both chargers at the same time. I am sure there are many others.
Good luck with your your setup.