My little brother will be 3.5 at our wedding. We've just got him a bow tie to match the groom and the dad's. No button hole - he'll just squish it or get annoyed by it. Basically anything delicate is probably a bad idea for little boys I think, they can be quite active.
Our florist said they could do wands but I've also seen them on etsy and other websites and they are probably much cheaper! I like that you could get them done to your colour scheme if you had one too.