When my oldest son was about 9, I was stationed in England, and became interested in heraldry and coats-of-arms. We designed this, to avoid the cheesy (and I'm sure unauthentic) one the "Family Heritage" vendors had.

It has gone through a few iterations. This latest version was created at The Treemaker (http://www.thetreemaker.com/design-c...ms-symbol.html). One can create their own, or they will provide varying levels of assistance, depending on your budget.