Levels and ADI
Both of these items can be found from many sources. My experience is that if you want the best, the flatline ops level and optional ADI add-on is the cream of the crop. They can be found through Grouse River or Sinclair international. Maybe some other canadian distributors, but I am not aware of any.
I also know that US optics makes a rail mounted level, but I am not a big fan as there is really no way to calibrate the level, especially for the cost of them. Other suggestions would be nightforce or vortex scope mounted levels.
Happy shooting.