Ive done a bit of research on the gun and the flashlight holder is one made by a few companies. Just google '5 position flashlight mount' and you will see heaps of them.
http://flatlanderoutfitters.com/images/commpicufh3.jpg
The flashlight is made by Feit Electric and they sell them at costco in 2 packs, it runs on 3 C batteries so is fairly chunky. The flashlight mounts do come in different sizes so it may pay to measure the diameter of the flashlight first.
http://imagecdn-0.findnsave.com/146/4381492
and here is a reference pic
http://www.imfdb.org/images/a/a4/TotalRecall-Vector.jpg
Quick sidenote, the front assembly of the flashlight moves in and out to change the beam, this is why the flashlight length is inconstant throughout the movie.