I have had excellent results and service from
www.radicalrc.com Dave Thacker, the owner, is both very helpful and friendly. He will answer any of your questions, sometimes referring to his FAQ section, which has a pretty good library of questions and answers for most battery issues that come up.
His battery selection shows the battery as well as the dimensions, weights, and so on. He will also do custom connectors based on your needs. Best of all, he guarantee's everything he sells. For example, I bought a LiPo pack from him about a year or so ago, it came in ok, but as soon as I put it on the charger, it puffed up. I stopped the charge and sent him an Email. He said "return it to me and I will replace it" no questions asked, even though I may have caused the problem.
He sells all sorts of packs, and individual cells, and, his prices are very competitive.
As far as a charger is concerned, well, I have a Duratrack Intepeak ICE charger/discharger, as well as a new Triton II EQ. I use them both and get outstanding results from both of them on all sorts of batteries and battery packs. The ICE is DC input only where the Triton II EQ is both AC and DC input.
CGr.