Out of the two fuel computer you are thinking of I would say go with the AFC. With the AFC you could also hook up the blue wire to get a digital reading of your O2 voltage which is useful in tuning. The PMS is overpriced and for the price you could get 3 AFCs. You can just lean the car out for now without the need for injectors if money is tight. You will probably need the injectors soon but with the mods you have you could get away with the stock injectors for a little while I would expect. When I had similar mods to your car the fuel computer was desparately needed as my car was also running very rich.