All,
You have been so helpful. I am leaning more toward the M2, just because I feel like it would be "enough" gun for him, would be fun for me to shoot also, and it seems like it would require a little less maintenance. What is the real difference between the M2 and the M4?
A gift certificate is not an option, as I think it would have so much more meaning to him that I picked it out. Neither gun is a poor choice and I don't see him bring disappointed with the outcome either way.
Dirtyb762 - I don't think my generous gift will warrent me a ring, I'm afraid. Maybe in a couple years.
Keep up with the good replies!