I'd love to guide you to the right answer if I could, but I just not sure. I know that KidNepro.com has some decent stuff for R&B & hip-hop.
HOWEVER, me personally, I own a Motif, Fantom, Triton, TX802(DX7 rack - I've used in the past), Roland JV-1080 and
a JD-990, I can there is no subsitute for the real thing.
Dont forget drums. What do you use for drums?
I personally just got done sampling all the drum samples in
my Fantom XR, Triton Rack, JV-1080 (plus the samples from the expansion boards HipHop, Techno, Dance & House) and aout to sample all the drums out of
my Motif Rack ES I just bought, and about a thousand drum samples I've found on the net.
I use Gigastudio32 on a second DAW just for drums. Lately I've had a bit of a latency issue on MIDI timing on my Cubase DAW to the Gigastudio32 DAW. I'm leaning toward a MPC 2000XL or a MV-8080.