I have an asus x501 laptop with windows 8. I know they have other models with touch screens, but I want to know if it needs any special software or if they have special screen connectors?
It all depends on the hardware in your particular system. Most likely the software is already in your computer, especially with windows 8. The connectors should be the same, Asus wouldn't want to be concerned with too many multiple parts for the same system; Simplicity is key.
If you purchased a touch screen or digitize compatible with your model number then it will fit your system turning it into a touch screen for most likely less than buying the system that way. You could also resell your current screen lowering your investment cost more. Google for touch screens with your computer model number and with enough searching you could find one quite affordable.
I once shattered the screen in my computer a few years ago. When I took it to a computer repair shop they quoted me $200+ to replace a 15.6" screen. After I searched online some I found a touch screen for the computer for $60 and installed it myself. I upgraded my screen for less than just replacing the broken screen. Since your computer isn't broken, search until you find a price you like. Price is of the essence, not time. Good luck.