Hi mate a 50 watt lipo charger will be good .but if your going to get a lot of batteries then I would go for a good power pack , a 120 watt or bigger charger a parallel charge board so you can charge 4 batteries in one hit as for batteries i think they normally come with the 1800 mah .if you have the money look at turnigy nanotech or zippy compact all of this can come from Hobby King if your in the UK it will be in your hand in 48 hours if not amazon is another good fast place to buy .if got a keystone 120 amp twin charger for £100 half price it's really good
My set up is 540watt power pack a mega 400 watt charger with parallel board the keystone 120 watt charger twin port I can charger 4x6cell 3000 mah and 2x6cell 4000mah in 45 minutes