I've heard SUSE is difficult to install because it requires a lot of customization, but I've never tried it myself.  I can say that Ubuntu is very very easy, it recognized all the hardware on the desktop and most on the laptop automatically (which is better than I can say for the reinstallation of Windows on the laptop...).  It does come with Gimp already installed, not sure about python, but there are some nice, easy graphical interfaces to add new packages and programs.  I've never heard of PCLinuxOS before, but honestly I'd trust Ubuntu a little more--it's based on Debian, which is a good solid distribution that's been around for a long time and has good community support.  However, if it works for you then go for it.  By the way, it sounds like they're using KDE for their desktop interface, you can get that or a couple others for any(?) version of linux, so don't let interface stop you.  What matters is the strengths and weaknesses of the distribution, support, updates, and maybe things like directory structure, which can vary a bit from version to version...and probably some other things I'm forgetting, but interface is pretty flexible.