Thanks for the kind words, but Crna Legija is right, this is around a year old now.. you should have made your own thread with those questions or sent me a PM man.
It is all copper tubing with a QEV attached, you can buy them from eBay.
As for range, I think I have another video on the same channel as the video I linked on page 2 that shows ballpark distances. I won't link it directly as one of the things I shot at is against the rules for this forum.
I haven't really tested it at any range higher than what is shown in that video.
Feel free to copy that design all you like, it isn't like I made it up myself. Don't try to copy my exact stock dimensions though, the trigger is in a bit of a weird place and is quite hard to reach even with by big hands. I should have done a bit more research on that before getting over-enthusiastic with my saw.
Good luck with your build, remember to check thread dates before posting in the future.