You can definitely put the battery pack and reciever forward, there is a nice compartment there, but you will probably need extensions for the servos and battery.......If you're using a flat 4.8v pack, you MIGHT even be able to squeeze the battery into the fuel tank area......there is a removable hatch for the fuel tank, so you could try it easily.
Don't worry too much about getting the CG towards the front of the recommended range....I balanced mine at 3.75" from the LE, the furthest back recommended in the manual, and it could definitely go back more without being unstable (I'm thinking from 1/4 to 1/2" more)

Mike