None. You might go slightly faster, but that's because of the weight savings. You would have to reprogram the pcm before you would see any actual power increase on the dyno, but the power would be from the new program- not junking the emisions equipment.
By all means remove the air pump, but leave everything else. I think on a '95 you need to get the airpump removed from the pcm or else you'll get a CEL though. Try removing the air pump relay first and see if it sets a code. If not, you're good to go and no programming necessary.