Graupner Hydrospeed arrow circa 1986

Hello to everyone, I am starting my retirement and looking for things to do.

I just unearthed my Hydrospeed arrow approx 24 inches long
I gutted all the existing motors servo etc. I am interested in starting over again with the new motor ESC transmitter radio battery etc.. anyone have any ideas on what kind of package I could put in  [You must be registered and logged in to see this image.] 

motor batteries radio etc. I am keeping the existing driveshaft and propeller and also rudder system
Thank you