Unlike you, I don't think that I know it all, certainly not about Rangies. Therefore I ask questions to find out more. You state above that "Land rover never did a spot lamp kit or harness" and yet the cable harness that was quoted is a Rangie driving light harness, not fog light, so I do not understand why you state they do not do a harness. Before you tell me that a driving light isn't a spot light, it certainly isn't a fog light either. It appears that those harnesses might be available stateside or, if not, easy to make up. I agree that reducing airflow is never a good idea, but why you need to bring up blocked radiators is beyond me.
The OP wanted some info, and that is what I supplied. I would suggest that he doesn't mount 12" lights in front of the rad aswell, but he hasn't said that he is, so I am going to bow out now and let you have the last word, as you seem to find that important. I hope that the OP found the info useful and hasn't found the slagging match to off putting. There is more than enough ****e on LZ ag without bringing it into here.