I have seen a few posts about Dpro not having much by way of a cool choir.
So I propose we make our own? Any vocal sample you've recorded could be sent to me and I'd write the sfz and then post that to Project 5.com.
You could submit as many or as few samples as you like and these would be placed in a folder for the sfz format map. Then as you play up scale the panned and level vocal samples would be spread across the stereo field.
The sfz format can have a lot of samples and each sample can have a unique volume/pan/level/keyrange.
On tune is not a biggie as each sample can be individually tuned with in the spec.