If you know the name of the host parents ,I suggest you to buy a pair of signets.I had made such signets with a
dragon and a pheonix and engraved both the English and Chinese names of my son's host parents.They totally costed $380.I think they are quite meaningful.But if you think it
is expensive,you can go to Tai Yuen Street of Wan Chai.
There is a shop which sells many Chinese souvenirs and
the cost is several dollars up.I'm sure you can find what
you want there.