A 2 stroke glow engine will sound like a weed eater. A 2 stroke gasser will sound like a big weed eater. If you want the rumbly warbird sound, you have to go 4 stroke. That's more money, but you do get more torque and better fuel economy with a 4 stroke engine.
A good point was made above about fuel cost. There's a reason that big glow engines aren't all that common, and that's the $18 a gallon fuel that they like. It doesn't take long for a gas engine to pay for itself.