To divide a pulse train by 2, you don't even need to use a PIC. There are many discrete devices that will do it. My favorite for these sort of applications is the 74HC390. It can be used to to implement various combinations of ÷ 2 up to a ÷ 100 counter at up to 50MHz and operates from 2.0 to 6.0V. It comes in a variety of packages including DIP16 and cost <$1.