A snare drum really looks like just your basic drum, with a high tension head. It's usually carried on a strap - I don't think you see them much in rock bands, mostly marching bands, bagpipe bands and such, but also in orchestras, I think. I think the kind I've seen some bagpipe bands use were pretty shallow, but I may just be remembering the practice drums hanging around my grandparents' and uncle's house.
Soooooo....If it were me, I'd just make a drum, just a plain old drum, a little shorter than you might otherwise, maybe with a shoulder strap coiled down next to/behind it if you're really good with fondant, depending on what kind of band the groom plays in.
Here's one Earlene did that looks a lot like a snare drum.