Hi, welcome!

For AV, I'd recommend the free
Avira AntiVir program. But please consider: I've no idea how it works on Vista (just XP), but it is supposed to support Vista.
Firewall, I don't know.
Comodo Firewall Pro v. 3 will support Vista, it's in beta now.
Look here.
CAVS 3 beta may arrive in October, but probably not with Vista support I'm afraid.
/LA