Hi

I just finished a Stinger for a friend and I think there would be room for a second tank on top of the gas tank depending on the size and on the system you are using.

I did not use the ABS hatch on the front, but made a scratch build area with the tank in the bottom. Since the tank comes out of the aft hole in the compartment, there was no need to take that hatch off. I generaly avoid ABS parts on planes, so it worked better to build the front up.

If you used the ABS cover supplied with the kit, ou culd likely stack the two tanks in that front compartment.

hope this helps make the decision