Rob...since ur into those guys, I bet u got their movies. Just "borrow" phrases, save them, then run them thru the windows sounds thingy. From this standpoint, I guess u do have to make ur own. But its fun.
Once I got a hold of a PC belonging to my OB-GYNE friend. He had a mike laying around...
That depends on what ud like "screeming" at u when u boot up. I'm a Trekker so I got these cool themes from startrek.com from borg to the LCARS menu.
Go to a site that u fancy thne search through them for themes.