You're welcome man. If you'd like my personal opinion, and, by that, I mean DO NOT let anyone tell you what to run, because that should be whatever works best for YOUR needs (Which is why I generally get annoyed by ads lol, they act like one product does one thing for everyone the same or something, when everyone doesn't have the same needs) But really, I'd say to look into this:
Which is what I was talking about before, but, really, if you've got a P4,, even a full FreeBSD would do it because you have some decent power there. I literally saw a Cell Phone yesterday with more RAM and a faster Processor, than my test machine. Like, it has a 1 GHz, and my test box is a Celeron 433 MHz and less than half the RAM too lol. But FreeBSD, can be customized SO much, it's like insane.
Linux can be too of course, I mean, when it comes down to the line, you DO have source for all of them, but BSD in general, just seems to try more at being FULLY custom.
I've heard AMAZING stories that were actually verifiable where people take BSD and slap it on a Server farm, and not ever even have to update. You strip BSD down to nothing but what's needed to boot, and what you need to run a Server, and "Hack" the Server portion into the Kernel, set it to deny everything but basic web traffic, and you have a machine no one is getting into without basically a jack hammer lol.
I know in Theory Linux can do this, but I don't personally know of a verified installation like that. And with RedHat saying they want to be like Microsoft; LOL more and MORE bloat.
There are even Window Managers I've NEVER seen Linux have available you can install from ports and Binary Packages in FreeBSD that are totally minimalist. Like, GUI on a 386 kind.
That's sort of always been the differences though between Linux and BSD; One focuses on PR, the other on not shipping broken out of the box like RedHat did that time lol.
Either way though, FreeBSD seems to be getting a LOT of use as a Custom Firewall Router combo kit these days. And the fact that a LOT of well known Security products, are using FreeBSD as the core, REALLY says something.