Okay, a little about this guy...
He is a retired Marine (so I think camoflauge)
He used to be a body guard to celebrities (Sandra Bullock, Uma Therman)
He is a dad to two youngsters (boy 6, girl 4)
He is married to a Sheriff
He has been doing various martial arts for many years (over 10 years) and right now only does boxing
He likes guns, knives, etc.
He is a huge collector of movie memorabilia ( '300, gladiator, sin city etc)
He is a big teddy bear who puts off a tough man thing.
I have known him for over 8 years and his wife asked me for a cake and when I asked her what she wanted it to be, she said whatever I wanted it to be as long as it said happy birthday....
So I have some ideas I guess but wanted to hear of some more?

Sounds to me like he's a man's man. I would try to make the cake as manly as possible. Like, almost comically so.

Lol, I just googled manly cakes and the second picture was of a sheet cake with Tom Selleck drawn on it. What about a fbct of a very muscular ninja (curly chest hair and everything) and he's saying, "Have a Manly Birthday, man!" Or like the Old Spice guy. "I'm on your cake." Then maybe you could make little fondant cutouts of some of the other stuff you mentioned and stick them around in the sides.

Ah! Thank you so much! You said FBCT and ninja and it clicked! Since he is into boxing right now I am gonna sketch him punching out some guy and then do the fbct onto the cake and make the cake kinda look like a boxing ring (the sides).
Thanks!

@rosencrantz Again thank you! I wanted to show you what the cake ended up looking like!

http://cakecentral.com/gallery/2052645

How cute ! I'll bet he LOVED it !