One thing to be aware of is that the Venture battery is described as having "a unique Hobbico connector." The tech notes at Tower Hobbies seem to indicate that this is a non-standard connector that is not available seperately. You will most likely need to modify the battery connection on the plane's electronic speed controller to a standard type if you want to try larger battery packs. You may not be able to find connectors to convert third party batteries.

Then again, Hobbico might just be blowing smoke and if you look around you may find the connectors somewhere.

Good luck and good shopping!