dimas,
I am new to solaris, but have discovered some great packages at
http://www.blastwave.org. They install all their packages separately in /opt so it doesn't interfere with anything else on your solaris system. They include a package downloader, which you need to set up, but after that is is plain sailing.
Anyway, you can install gnome, kde and many others from here. Kde's kget is in kdenetwork, which may be something you could use, (i have not installed kde myself in solaris). Probably other offerings are available from here.
My absolute favourite is d4x (downloader for X), but this seems to be linux only at present.
tobyl