You could get around cutting the wing for fuel tanks if you make removable firewalls. You could also recess the firewall to give you more room. Of course if you are allergic to alcohol fuels, then electric is your only choice. A guy in the club runs the OS 91 gas two stroke and it has a great sound. It almost sounds like a bigger engine running on a cannister set up. Very quiet with a nice tone to it. Not cheap, but his does run really nice...
I had some of those giant lipos at the house that belonged to a customer. Literally a brick sized Lipo. I was not all that fond of keeping those big suckers in my garage.
Be careful with those MAS three blades. I have seen them throw blades while never have a ground strike or any other damage. I had a few that center holes were WAY off center too.