depends entirely on your goals, $ willing to invest, etc. Mark D (here on the board) has great chips available for 17/19# injectors.
Unless I'm wrong, 302 Ford injectors are either 36# or 42#. You don't need anything over 21# unless you're have forced induction (turbo / super charger).
If you're keeping the motor stock, just get 17# injectors from an M50 and a chip from Mark D. You'll see the most gain for the dollar that way.