Regarding the choir sounds, link your Tyros 2 to your PC and use the editing software.
With a bit of twiddling you can get some very good choirs. I'd like to see some more from Yamaha available to download, but it's the only way to make them better for the time being. I've managed to get a decent sound for Mike & The Mechanics Living Years song.
The editing facilities are spot on. I wont be using many preset sounds once I've gone to town with creating custom voices. I have to put my own stamp on any keyboard I purchase lol