What he's talking about isn't exactly a '90s full tower. But the pico psu bundled case has already been suggested a couple of times and he keeps going back to the same one...
If you know that you want a dedicated device to just firewall, then a tiny case is ideal. If you're not entirely sure what you want, and may want to do something like virtualize the firewall and turn the hardware into a vm server with a few drives, that's going to be really hard to cram into a tiny case (and cooling the added hardware would depend on cramming tiny fans into the tiny case instead of using a big low-rpm fan in a bigger case). For someone who's already changed their mind a dozen times about what they want, having the flexibility to repurpose the box is probably useful, even if the box may end up being larger than it needs to be.
Thanks a lot guys.
For a little clarification, I'm actually not opposed to a small case at all. In fact, smaller the better. I'm also fine with a dedicated firewall. I haven't really changed my mind so much as I have been trying to keep open about possibilities.
I would be totally fine with a rackmount firewall. You could even say it's my preference since I have a small rack sitting there already. But, when it comes to small cases, the one thing I don't want is noise,and the other thing is that they may lack performance or ability to have at least 3 NICs which I want so I can have a DMZ.
For instance, I was really intrigued by the APU2C4, but I read that when using OpenVPN, it was only getting like 40 something Mbps if I remember correctly. It also seemed to be pegging one of the cores while the others were sitting idle. Otherwise, it seemed like a great solution.
Another issue I face with the small cases, is that the board may have only two NICs but then there's no way to add a PCIe card.
I only started leaning towards the i3 because so many people were saying that was the way to go. I really don't need to expand. I'd rather build specific and put the extra money, if any, towards the next cool project.
I hope this helps paint a better picture. You guys have been great. Thank you.