Is this a request for some?
You could look at the Jazz vocal sample set from Zvon. Don't have a link handy sorry. He's always hawking it on KVR though. Reviews have been very positive so far.
I would hire a singer.
Why...Vocal Planet of course! :-)
Lot's of articulations of multisamples and the several are singers are from Take Six.
I second Vocal Planet. The Take Six-ish oohs, ahs, doos, dahs, etc are absolutely amazing.
Another similar package is a Kurzweil-produced 'Take Six' collection of samples for the K-2500 sampler(which I have not heard):
a $120k business degree will get you a job on Wall Street - a $120k Berklee degree will get you a job on Beale Street...
The Kurzweil disc was done really well and was specifically designed to take full advantage of the internal architecture of their synth extensively for all the programming. We studied their work pretty closely when we got ready to do our Jazz Vocal Multisamples for VP as a reference. I think we got a more lively sound in our recordings on VP, but the Kurzweil disc has some unique things to it too that are different than VP.
The Kurzweil Take-6 CD-ROM is a great "must-have" disc to have if you have a Kurzweil, but I know for sure that trying to convert it to other formats would be next to impossible and would have very disappointing results.
VP doesn't have this problem, since it was designed to be "convertable" and cross-platform from the beginning and works well with all the current samplers.
VP converts really well cross platform. I know that Garth of Chicken Systems worked very hard in the early Giga days to iron out that conversion process.
This is maybe not exactly a jazzy thing, but it has a ton of Vocal Planet syllables in it, and also another really cool library of Eric's, Metamorphosis. One of the great things about the VP vocal sounds is that they have some total low end balls. You can make really fun grooves from them. There is a literally overwhelming amount of this kind of material, and these human percussion type sounds are just one subset.
I would not worry about VP having been farmed into oblivion. Ha. Good luck with that. There are about a zillion possible combinations of all that material. A person would die trying.
Love the Squeegee Man track, Bruce!
I demoed the spectrasonics vocal planet - superb ! ($399 is a considerable investment though)
As for the Zvon samples, they are not multi-samples unfortunately.
I didn't explore the kurzwell samples as I am more after female vocals rather than male.