Ok here it is and I'll probably get flamed for this:
can you have a chip and a programmer or is it one or the other?

 

The chips are used in the older mustang more like the 87-93 5.0s. 94+ use a handheld programmer such as diablo or sct.

 

a hand help will let u tune certain thing yourself and you are also able to have a few custom tunes put on the tuner as well which u would have to load into ur car. a chip can hold custom tunes which stay in ur car and can be changed by the flip of a switch

 

You would use a chip if you were planning on running nitrous. You would just be able to flip to the nitrous tune. Otherwise I would just go with a tuner. You will be able to adjust some of the settings yourself.

 

You can use both. I bought an SCT programmer when I installed my Procharger. I went with centrifugal because I heard instant boost from twin screw chargers hurt your main bearings. " Everyone is entitled to their own opinion" If you opt for centrifugal, just so you know, you'll have to send your ecm out to get retuned if you go Paxton or Vortec. Or you can just buy a hand held tuner and get a good custom dyno tune. I had a Diablo chip that came with the kit but I opted for SCT instead.