When I need to look for something we don't have in our CD collection one of the first places I check is called www.soundrangers.com another one I use is www.sounddogs.com  I'm sure there are other sites out there.  These are pay sites, but the fx are usually pretty cheap and a lot less time consuming than trying to build a cue yourself.  I'm sure there are some free sites out there, would be interested in know what others use too.