I would ask the artist on etsy who sells her TF2 panties. They have some tf2 fabric and says they can make any character you want.
Obviously, its been a while since you posted this, and you probably already found something for him, but in case you're still looking; here are some ideas.
TF2 Tie blanket : If you wanna do this, which I will tell you is fun but at the same time nu fun at all, I would suggest you get the colors you need, like say you're doing a medic one. Get the team color for the front, and the opposite for the back, and then get very little white, red, and I believe yellow. Cut out the shapes and things of the medic, like his cross and speech bubble thing, and a little bit of black for his pack, and stich them in places on the front piece of the blanket. Once you've got that, you can lay out the pieces and begin cutting and tying.
As for the charms and dolls, I would say to be very very careful. I ordered some dolls from a girl on etsy, paid her, and never saw my dolls but she greatfully used my designs for herself. Took me six months to get my refund from her.
You could always get him a print. I find that to be very pleasing for a christmas present. I always give my boyfriend underwear, candy, and one of my own prints for christmas, his birthday, and valentines day cuz they're all around the same time. But you can go on dA and find a picture or fanart of his favorite player (mines the Heavy) and buy a print of it, then get it framed and give that to him.
I got a framed print for my lil brother for christmas, of the Blu Scout cuz its his favorite player, and he loved it.
