hello, i'm a bit confused with choosing the custom search for my search engine.  i just saw a google custom search engine on the net, the url of which is http://search.sweetim.com.  this search engine is showing results very close to the google search itself. So can any one tell me that which google custom search should i use? either the json/atom search api or the xml search api. because both are the different things and both have paid versions too.  and i want to make custom search engine which searches the entire web and not any specific website, as search.sweetim.com has done. the user types the query and it searches the entire web and displays the results. Any help would be highly appreciated.

thanks and regards,