what to do next

ok well I'm about to spend some cash but there is a couple things i wanna do but i dont know what should i do first, i already got long tubes and full catback x-aust, cold air, duel centerforce 373's, now I wanna beef up the air/fuel (adjustable fuel reg., bigger injectors, mass air and thottle body) but i dont know where to start, cause I only got about 300 bucks, where should i start to get the most performance for the cash. Another thing, I tired to put a diablo chip and after puttin it in, the car wouldnt stay started at all, we put it on the dyno to tune it and didnt get any performance, lost horsepower, i was just wondering if anyone had good luck with the diablo chip 94-95 file on there cars.