In addition to the above chargers I would recommend the [link=http://www.fmadirect.com/Detail.htm?item=2218&section=45]CellPro 4S[/link]. I don't personally have one but have heard nothing but great things about it.

Last year I purchased a new Hyperion EOS1210i and two LBA10 balancers. You can find it at BPP for about $225. I can charge up to two 6s packs at the same time with this setup. Already having this charger meant that I did not have to upgrade when I build my T-Rex 500 last month.

Good luck with your decision.