Hmm nice questions, means that your really interested in linux

always a good sign.
Most distributions have support for a good amount of wireless connection hardware., you just have to compile it into the kernel. Now i haven't done fedora's install but there should be somewhere in it to a network setup and have the option to set up a wireless part. If not that might be something you have to go back and install after the initial install.
As far as the other distro's you touched on.
Suse, is a very popular get your feet wet type of os for linux. It comes out of Germany so make sure if you want to use it, you get the English install. Unless you want to learn German

It's highly configurable.
Slackware is a windows replacement, meant to look like windows in essence. Think of it as windows without the bugs

, and quicker bug fixes if there are any. Also a get feet wet os.
Mandrake, I've never personally used or any system that uses it but, it is highly recommended by the community in general for starting out as well.
So in other words you picked out a couple of distro's that were all good choices for getting into linux without diving so far in headfirst that you get lost in the muck.
Personally it comes down to a choice, I'd recommend either the fedora project, or mandrake. Course as i said that personal preference.
Also if you'd like to just see what linux is without having to install it there is a distro called Knoppix that is a live cd (basically a bootable linux from a cd rom, there's also linux distro's that fit on floppy's) These come with hardware detection that will tell you quite well if your hardware can and would be a issue if it has trouble finding it.
All these distro's mentioned above can be found at
http://www.linuxiso.org . They are also the latest versions
of it on said site.
If you wonder about the multi disc iso's, they are generally cd's bundled with software such as
kde gnome Open office