Buying Lipos today, need advice

[Nick]

I'm ready to buy my Lipos and charger today but want to make sure because getting stuff posted to the UK from America is becoming a nightmare for me, so wan't to do it as little as possible.

I will be getting the e-STATION 902 for $300 at TrueRC.

Then 2 packs of 4000mAh 3s1p from Maxamps.

Now I need a balancer and havn't a clue which one, so please help. I know nothing about the connectors and where they are used? Anything else I need?