Are you talking about an actual in bed "camper" or a "topper"? I know there are quite a few members with "toppers" but I haven't seen an actual "camper" for the Sport Trac.
Are you talking about this tent for the bed of the ST? It was a post in the past couple weeks. If it's what you're referring to you could try a search.
About 5 +/- yrs ago I did see someone with a cab-over camper on the back of their ST. Do a search of posts over 1yr old and you should come up with something.