I was going to suggest Advil Cold and Sinus too but the gel caps since I find they work so much faster.
However, it totally makes sense now why I can't find Advil C&S on the shelves when I go shopping in the US anymore. I had no idea it was a behind the counter thing and you had to show ID to buy it! Come to Canada - we leave out all the good medication on the shelves and as far as I know, there is no daily limit! I guess this is why I can't find Advil Super Strength either? I can get the Advil 200mg but not the 400mg liquid-gels (the only thing that works on my migraines). It is so much cheaper to get medication in the US. Now, the only things I can get is the Target brand of Benedryl and Gravol. I guess you learn something new everyday
Hope your son is feeling better soon!