You can usually get OS X installed on any PC. However, certain devices will almost always need hacks to get working (if you can get it working). Audio, WiFi card, SD card reader, etc. OS X is just a modified variant of BSD Unix, so there is a fair level of community support for this sort of thing. But most people wishing to run OS X on a PC research which components/laptops are compatible, then buy the hardware. Not the other way around.
If you don't need to run OS X natively, you can try running it in a virtual machine. Hardware device support tends to be a bit better in that case since the virtual hardware is standardized. The major VM programs put in software blocks at Apple's request to prevent you from doing this (their...