use VMware player to install Gnome and KDE
Gnome. If you want KDE, you can use Kubuntu, the KDE derivative of Ubuntu.
Ubuntu - GNOME Kubuntu - KDE Xubuntu - Xfce Puppy Linux - JWM Damn Small Linux - JWM, Fluxbox Fedora - GNOME (default) OpenSUSE - KDE (default) Debian - GNOME, KDE, Xfce Red Hat Enterprise Linux - GNOME Linux Mint - GNOME Xandros - KDE PCLinuxOS - KDE
This is generally a matter of preference based on what user interface you prefer (KDE in Kubuntu, or GNOME in Ubuntu). They are both produced by the same company, although some believe the Ubuntu distribution receives more attention and polish.
Gnome There is a KDE version named Kubuntu, however
Desktop environments.
Everything will still work. However gnome applications do not interact with the desktop environment of KDE as well as they would with gnome. The differences will be mainly superficial. You can always remove the gnome applications later and replace them with kde ones if you want.
Ubuntu uses GNOME by default. However, a KDE version is available, named Kubuntu. It doesn't have all the bells and whistles of its GNOME counterpart
All Debian ISOs are "full-featured"; you can use any of them to install any Debian programs. The KDE and GNOME ISOs are probably best if you want a desktop system, and the netinstall is a better solution for servers and systems you need / want to customize heavily. However, nothing stops you from, say, installing KDE on the netinstall system, or installing Apache on the GTK system.
There are many desktop environments in linux. Most prominent would be: KDE Trinity - KDE fork (response to KDE 4.0 dissatisfaction) Gnome MATE - Gnome fork (response to Gnome 3.0 dissatisfaction) Cinnamon - Gnome fork (response to Gnome 3.0 dissatisfaction) Unity - Ubuntu's desktop environment (built on top of Gnome 3.0) XFCE LXDE There are many more. Also, there are window managers that have comparable functionality (ex. Enlightenment)
there are too many Gnome, unity, kde, ....
Yes. Both are fine.
GNOME and KDE.