Fog lights

I have a 1999 dodge Dakota and I am looking for some fog lights. I have found a pair I like http://stores.channeladvisor.com/kayee2501/Items/FG-DAKT-0104-HALO?sck=14484402

They say they are for the 01-04 but what is the difference between those years and the 99's.

My truck never came with fog lights.

If it's the wiring cant I just wire them to a separate switch?

If it is the size cant I just make my fog light opening bigger or smaller if need be?

Or does it have to do with the mounting?

Well I have got the fog lights on and It wasn't that had to mount them, if you check out page 2 of my cardomain at the bottom of it I explain and show pictures of how I got them in there and they will stay without an actual "bracket"

http://www.cardomain.com/ride/2143892/1