My recommendation would be Online Armor,
but since you said "a new laptop" I must suppose that there will be Vista installed on it, right?
In that case you would have to use Comodo, since Online Armor is not yet ready for Vista systems.
Both firewalls mentioned, ie Comodo and Online Armor are at present the best guard, both complete with efficient HIPS guard, so together with Avast you will be perfectly protected against any mishaps.