I don't think that it is just as easy as switching the air dams. If you are meaning to switch to the model year 1999+ round style fog lights, then I'm pretty sure you'll have to switch to the 99+ style bumper. If you PM espnfreak or 95XLT, I'm sure they can give you the details on switching the bumpers.
If you do decide to switch bumpers to get the round lights, I'm sure that your current wiring can be used for the new lights without a problem. Just connect the positive on the truck to the positive on the light and the negative on the truck to the negative on the light. Easy as cake.
BTW: If either of you decide to switch to the new bumper, I might be interested in taking your old air dam with the square holes for the fogs. Provided that it is grey and in good condition.