RE: electrifly siren
We can only recommend what would be listed in the instructions or something similar. Anything else would be up to you. Take measurements of the motor area and see what may fit. Likely, you'll have to do some rebuilding of the nose for anything much different that what's already there. Weight is the major consideration for models like the Siren. Be constantly aware of what you're doing with regard to weight, and keep the weight down.