I'm still not really well or here, but I figured I'd send this to you telepathically. So here it is. Listen carefully, since I only have so much strength/energy to send things.
My understanding is that Slackware is behind times. This might have changed (don't know) but it seems they've been lacking in a lot of areas. But some people do like it. It's certainly a more manual system too, which can be a bonus to learn the command line.
My personal favourite is Gentoo (gentoo.org). A lot of people don't like it, several reasons, among them that you compile everything from scratch (although you don't have to for installation and the most recent version has a GUI installer). Just depends on how you install it though. You can actually download the ISO image, and most of it is already compiled. Add to that, you can have the compile system make images of the compiled programs so that if you ever install on another machine (or the same machine) with the same code (processor) it's even quicker. Then there are programs like ccache (compiler cache), and other features to speed things up. So basically, what you have to do for sure is some configuration type things that pretty much every distro has you do in some form or another.
The bonus here is that you learn the command line a lot by going through the installation manual. Plus you learn the distro specifics. And you can even learn how to configure the kernel without a GUI (graphical user inferface in case you can't remember or know).
I know some here on the HFX boards really like SuSE. I've tried it and it's quite decent now adays; I just prefer Gentoo for some reason (maybe because I don't use a GUI although you certainly can with Gentoo).
Pretty much any major distro should allow what you want to play with. To be honest I don't have much experience with printing and such in Linux (although it's not hard, I just have no use or no secondary printer [and no printer switches]).
As far as HTTP/FTP, it's pretty simple. You just choose which daemon you want to use (apache is common for http, a common ftp is vsftpd or even proftpd or pureftpd). Take your pick really. Then there is proxies and you have choices there too (which btw, choices is what Gentoo is all about).
So my advice to you would be to look around. Say check SuSE, Gentoo, Slackware... and any others you might have heard of. I will say I'm not a huge fan of RedHat, but a lot of people are and there seems to be a lot of information out there. But that's not to say other distros don't have that. Gentoo boards are awesome, and I think I remember SuSE having decent support too.
And you can always ask here. I usually lurk around here, but don't reply as much lately. But if no one responds or it's something I know, I'll try to get a reply in.
Good luck and hope that helps.