The Thunder AC6 sold by Hobbypartz is AC/DC, charges, lipo, life, NiMh and NiCd and has a built in balancer. If an when you go lipo, it will do fine on 2S lipos. Its a 50watt charger.

http://www.hobbypartz.com/thac6smbachw.html



If you want a little a little more power, their Thunder AC680 is an 80watt AC/DC powered charger for ~$60. Either one will be hard to beat given the price and their features.