To be perfectly honest with you, you have to at least 'trust' the likes of av-comparatives.org and/or matousec.com to some extent.
If you read up on what Matousec is, and what they stand for, you will realise they're not selling any BS. On the contrary. Read up on the site and you will see what kind of testing level is used to acquire those results, AND what kind of effect they have on the vendors reactions to them.
When comparing the two websites and considering that one compares the standalones, and the other compares the Firewall protection of mostly suites, the wise decision would be combining what is a good standalone AV according to av-comparatives, with a good Firewall according to Matousec, and that's exactly what I did.
I know both sites, and they are indeed serious ones, and both Avira and PC Tools' Firewall are good products as well. You've made a wise decision. However, the "best" product will still be another one according to some other equally serious and reputable site. And the next tests by av-comparatives.org and Matousec may have entirely different results. There is no single product that stands out at this moment, and given how things are changing, there isn't likely to be one in the future.
The days of "innocence" are over. Malware is not any more the work of some bored or disgruntled teenage computer whiz somewhere. It is the work of highly organized, multinational, professional criminal gangs with a high level of technical knowledge and competence. I mean Ph.D. level - often literally. They increasingly know how to fool security products and render them useless by themselves.
So, use top-tier products, as you are doing, but be aware of their limitations and of the ever-changing landscape and state of things.
Throw in a light but effective Malware agent like Malwarebytes' Anti-Malware, and you will REALLY have yourself a FULL circle.
No doubt you'll come nearer to it, but the point is, the circle can never be fully closed these days, if it ever could. It is very important that you have this in mind. And I would add another very essential component: Secunia Personal Software Inspector (in this case, I don't know of any real serious alternative). KIS partially implements Secunia's engine and database for its "vulnerability scan", but the real thing is even better. As opposed to being reactive like a usual antivirus is, it is
proactive by closing all known doors a piece of malware could use to gain access to your system. It is extremely important to have
all your software, OS and apps alike, fully updated and patched. Today, this is even more important than having an antivirus, as top specialists like Dancho Danchev always point out.
I was thinking about going with Online Armor Personal Firewall (tied for 2nd in matousec.com's latest test with PC Tools' Firewall Plus), but after going to it's official web site, I found that they don't have x64 support at the moment, plus I don't think it's 'officially' 7-compatible yet.
Indeed, Online Armor doesn't have a 64-bit version yet, although its publisher, Tall Emu, says that it is in the works. But version 4.0 has just been released and it does support 32-bit Windows 7, fully and "officially".
I have decided to stick to 32-bit for now, because in my current configuration and conditions there would be no real advantage and some real hassles for me to go 64-bit. So, this not a problem for me. If and when I decide to switch to 64-bit, Online Armor will certainly already have a x64 version. But then, of course, the security software landscape may be radically changed and I may just as well choose another product.
Many people are also adding another layer of security with a hardware firewall, a specially configured router to serve that purpose. But in my conditions, I think it's overkill and an extra layer of complexity that I can do without.
I am extremely disciplined and paranoid about data file backups, but not so much with system images... 