re: Mallets

If you have a lathe, I say make your own.  You can tune it to the weight and size you want and you can make the handle so it fits your hand comfortably.  I don't carve with a mallet but I use my carver's mallet with bench chisels a lot.  I prefer one with a heavy head but also with a head small enough that I can grip the head itself for fine work.  So a small, heavy head requires a dense wood or metal.  Corelz suggestion for Lignum Vitae is a good one.  I like the dampening and feedback I get from a wood head so I prefer that to a brass or urethane head. 

If I was buying one, these from Lee Valley look good.  And though I don't think it would suit me well, I know the Wood is Good mallet Rich mentioned is well-liked by a lot of folks.

If you want to get rid of some pesky cash that's been bugging you, I really like the design and materials of the Blue Spruce Mallets.  The head is resin-infused for durability and it has a steel shaft that joins the handle and head and also adds some weight which, IMO, is an advantage.