The 12F675 doesn't have built-in UART capability, but there are tons of PICs that do. For example, the 12F1822 looks like it meets or exceeds all the features of the 12F675, has built-in USART, and it's cheaper. Unless you really feel like making your own software-driven UART (an effort I would certainly applaud), then I highly recommend purchasing a UART-enabled PIC.
Either way, don't forget the MAX232 (or similar) chip. The voltage levels on your serial port are very different from the logic levels of your PIC.
-Dan