I recommend Symantec Corp Edition AV. and If you must Internet Security with Firewall. However I do recommend only using AV. If you have the 4500 set up well and have Firewall on. There really no need for Software based firewalls. I've been running with out for years. I would only recommend software firewall if you really need it, have a network that requires it or have security needs.
Reason being is that it's less one thing to have to trouble shoot should something arise and it's less TSR program taking up system resources. Most AV and FWs are bloatware and hate it. But it's a necessary evil. I run Norton AV and Spy Bot on my systems and been safe and clean thus far. My 2 cents.
I agree that you can leave out Software Firewall. Anyone that wants in on your system will laugh at any commercially available firewall, and most bots and randoms will be stopped by the SPI and firewall on your router. I cant agree on Symantec though, not even Corp Edition. While I agree its the lone star in the HORIBLE line up that is the Norton line, if your trying to get away from bloat, stay away from Norton.
As for what to use, I have used Avast Free both proffesionally and privately for a while now. They offer a boot scan, decent heuristics(best in the free catagory) schedualed scans, and no pesky firewall. The most common complaint is that it makes a noise while it updates. But you can litterly turn that off in 5 seconds.
Now if you can spend money, and to compare apples to apples, check out ESET's NOD32. Hands down best heuristics(the ability to find a unknown infection) and also a very small foot print. This is seriously one bad ass AV.
As a alternative, and one of the few good AV you can buy in a store, check out Kaspersky. If you want a firewall integrated into it, this is the way to go. One of the few I didn't have issues with. Very controllable, but takes some tinkering.
As with anything though, do your own research. Some good places to check out is Bleepingcomputer.com, CNET and Tom's Hardware for reviews.