I had 'G-Flightsystems' make me a case for transporting a 500 size heli and all support equipment (inc batteries and spares) a few years ago.
It has been used a couple of times to take a heli/kit, safely and fully protected with me to Australia (for work).
This bespoke case was sized for the heli, tx, charger (inc power supply) batteries and spares. It'ssturdy construction and will cope with many more journeys across the world or whereever you want to take it.
I no longer have the heli or need for the case and therefore I has to go. It is 96cm x 50cm
Flight Case 500 Size (loads of room for heli, radio, spares, charger etc) - a set on Flickr
Originally cost was a little over £200. Looking for somewhere around the £80 mark. Ideally pick up only(I am in Preston Lancs) but may be able to 'post'/ship.