Help! Battery packs

[boaterkid333]

I am getting the proboat Miss Geico once i get my paycheck. I am getting an X642 to bump up the speed but now i have no idea which batterypack from hobbyking i should get. Hobbyking has all kinds of different brands i have no idea what to pick from.
From my research i found out i need something like 2s, 5000mah, and 40C

turnigy?
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=16194

or these nano techs? light batteries make the boat go faster?
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=11934

Help me out here :help: thanks a bunch

[Diesel6401]

I am getting the proboat Miss Geico once i get my paycheck. I am getting an X642 to bump up the speed but now i have no idea which batterypack from hobbyking i should get. Hobbyking has all kinds of different brands i have no idea what to pick from.
From my research i found out i need something like 2s, 5000mah, and 40C

turnigy?
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=16194

or these nano techs? light batteries make the boat go faster?
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=11934

Help me out here :help: thanks a bunch

I run both those packs (well I dont have the nano 5000mah I have the 6000mah ones) both are AWESOME packs. Biggest difference over the nano vs the regular turnigy packs is you can charge them at a high rate. The difference in weight isn't enough to make a major difference in speed.

[gek1946]

I am running the same compbination with the prop no. and the 5000mah 40c batterys. My run time isnt good about 10 minutes. Is that ok?
what can you tell me about going to the 3s batterys at 11.1 hooked in series using a stock control module

Thanks
GK