Something you could easily do yourself. Just screw the tank reg on the tank...you don't even have to loctite. You can buy bottles from luxfercylinders.com
or Gramps and Grizzlies:
7203 Arlington Ave Unit F, Riverside, CA 92503
Phone: (909) 359 4859
Fax: (909) 359 5208
I'm sure you could buy them other places too.