Go for the freebie zonealarm and upgrade if you feel you need the extra features.
I have used Zone alarm for the last year + and had no problems.
It also gets good reviews.
And for AV - sophos. No contest. I have used it in my last 3 workplaces and it is excellent. Especailly as an office licence covers the home PC! Very helpful tech support, 24/7/365. YOU can download a free trial at
www.sophos.co.uk
Memetic.
P.S. happy to be a plugger, i'm on Pipex too.
- or not I just re red Evo's post!
If you have a spare old PC this looks interesting...
http://www.smoothwall.org/