Two thoughts:
If you believe in God and Jesus as revealed in the Bible, you probably believe that God is able to communicate to man in any way He chooses. In the light of this, the fact that there are no divinely-inspired pictures of Jesus (such as you might concievably find in the Bible) ought to make you wonder whether God wants us "visualize" Him in this way.
Second, is a picture the best way to know a person? I might see a picture of an individual, but unless I READ descriptions of that person's character, or READ something which that person has written or transcriptions of something they said, I can't really KNOW the person. If I want to really know someone, I need to read a letter from them or talk to them in person or on the phone.
My point is simply that, while pictures seem nice, they can actually get in the way of getting to know who Jesus is or having communion with Him personally. It is possible that a person can look at a picture, get a nice warm religious feeling, and never seek to know Him personally.
Just some thoughts.
(BTW, the most disturbing thing about the "picture" of Jesus with the Barrett 50 isn't the Barrett 50, but the absence of the cross. Without the cross, we are alone and without hope in the world (Ephesians 2:12). JMHO.)