As far as i know he will supply that but you will need to check. He told me he supplies them with an 8mm barb and you heat hose on and push it on. I use 6mm and was perfect.
Word of warning, you cannot use double eared o clips you can only use the single ear ones Gardiner sell due to the reel design inside. You can just use a jubilee clip but they always leak with me for some strange reason lol.
^ That's in reference to the fitting inside the drum.
If he doesn't supply fixings which i would be surprised with its just a screw thread and 6mm barb same with the water swivel which i must also say is good and doesnt leak
Check first though, if he doesn't supply the fixings tell him he still has my trust o clip pliers lol !!!