HP Omni 120 for Gaming?

Uhm hold on. You seem a bit confused on each layer of 'defense'. While a firewall with NAT can protect worm spreading (your talking 20 years ago tech now) from general, find device connected to internet, infect device; that is all a firewall does by blocking the most likely ports. When access any sites, even legitimate ones, virus code can be in the Jar files, the actual photo images, even in video streams now, so you need a Antivirus to protect against the billions upon billions of variations. Malware is different that it doesn't 'damage' files or corrupt them as in the case a viral attack (think of malware as telephone solicitors and viruses like cancer), they are only going to persuade you (social engineering) to do something the program intends, be it turn OFF your AV, buy thier 'fix' which actually causes your system to attack other systems (botting), or to just get your information (Credit Card # address etc for the 'purchase' of a fix' then turns into them fraudulently using your CC). So a weekly scan with Malwarebytes manually run (or buy the package for automated scans) will reduce this problem that Antivirus can't "See" because they don't see damaging attacks.

That said, it is a fact any computer, even with a firewall, accessible to the Internet has been timed to last just 10 minutes before being infected. EVEN if fully patched.

That said, there is a myriad of antivirus software out there, and as a developer you know some is good programming some is bad. Your jar files should NEVER have the marks of a virus, or the 'user' of your code will also suffer this problem when they need to use your developed product. So that would be a change on your skill set to match the current business field, instead of expecting the the field to change to what you produce. If you have a developer machine connected to the Internet then you need to have antivirus on it, and antimalware, that is just a fact. EVEN a sneaker-net based isolated system is NOT safe from viruses (have you ever heard of STUXNET? If not read up). If there is any input interactions (connect USB, insert software, etc.) there is always a way for viruses to enter. EVEN big name developer AutoDesk had one infect the GOLD Disk as they went to production, costing the company millions as the very expensive software had to be 'recalled' and reissued after infecting many systems worldwide.

I recommend AVG and AVAST! as both are free, highly reputable, have low 'impact' on a user's system, and most of all are very successful in stopping viruses. In both cases specific directories can be set to ignore as well, but you be foolish to ignore all JAR files, as that would also include any from the Internet causing your system to be back here having problems again. Like any software you can 'remove it' but that would be like leaving removing your wallet and just laying the cash on the side of the street and believe no one will ever 'steal' it. It just isn't' logical.