We, too, used Disney Videography and were so underwhelmed by songfreedom..which is now the only way to get songs for your Disney Videos.
For our EPCOT bridal videography, we used Hey Soul Sister....
But we still haven't picked our wedding montage song. So tough. We live in St. Louis, where SongFreedom is headquartered and my wife, who is a photographer, uses their site and is in contact with them.
They just signed a number of new artists, the most mainstream of which is Colbie Caillat. One of those songs has meaningful lyrics to us and once it is up on the site, we will probably choose it. But it's not even close to instrumental, if that's what your looking for.
Not a lot of mainstream...but because we use them, we are often in contact with them. They are nice people. They are trying.
Man...12/11 is so close....they are trying to get some other mainstream artists signed but it is not a fast process so probably not before your 6 months are up...I wonder if they would give a month exemption.....doesn't hurt to ask.
Good luck