Go for it! Kangers are nice.
You only need a standard Ego battery but I would recommend the twist for variable voltage. The 900 is out of stock on that site you are using but you can either get the bigger 1100 or wait or buy it from somewhere else.
IMO the 900 is the perfect size.
http://www.ivapour.co.uk/janty-ego/ego-batteries/650-ego-c-twist-battery-2.html
http://www.vapeland.co.uk/ego-twist-900mah-101-p.asp
thanks ordered!