i previously post PIC16F870 PIC16F872,PIC18F2220 as choice

fast view of those :

PIC16F870 PIC16F872:
  • 22 i/o
    2K code memory space
    need external crystal
    64 bytes of internal EEPROM
    6.29$ CAN

PIC18F2220:
  • 25 i/o
    2k code memory space
    don't need external crystal
    256 bytes of internal EEPROM
    9.96$ CAN


Both are good and provide more than what you'll need. I'll prefer use the 18F2220 to save space for crystal + you'll get more i/o.