The biggest question you have to ask is how comfortable are you with Linux? If you never used it, stick with Windows. At least with Windows, you don't have to worry about compatibility issues, finding drivers, etc. It just works.
Far as laptop keyboards, I use always an external keyboard anyway for I do too much typing, and prefer a full size keyboard. I've had both HP and Dell laptops, and the keyboards felt the same to me, but again, rarely use them.