well i must admit your going with a good gun for your first rifle. but i donno it this was said or not what brand were you going with?
and maybe down the road you should think of getting a G&P V-stock for your G36 it would let you store a large style battery in the folding slether stock. but thats an idea if you would like to got a larger battery.
heres a review on the stock i you like the idea
http://www.airsoftcanada.com/showthread.php?t=22633