Hi MSH,
I´m producing the same Musicstyle like you do. I think the update to 7.5 will never be wrong like roel said. The most Plugs i´m using are naturally sounding plugs, of course for SOUL (70´s & 60´s), RNB, Funk. I will give you a short list what i´m sing for my Music, maybe it could be something for you, if you haven´t these Plugs:
Drums: EZ Drummer 2, Superior Drummer 2, Addictive Drums, NI´s 70´s Drummer, NI 60´s Drummer, NI´s Modern Drummer, Battery 3, Spark VDM, Best Service Drums Overkill
Bass: Trilian by Spectrasonics. Nothing else more for Bass if you have this one.
Keys: NI Electric Piano 1.5, Scarbee Vintage Keys, Arturia Wurli, Galaxy II Pianos, Galaxy Vintage D, Alicia Keys, NI´s Vintage Organs and Session Horns for Brass
Strings: VSL Special Edition, VSL Appassionata Strings 2, East West Symphonic Orchestra, NI´s Session Strings
Guitar: Music Lab Real Gtr. Series, NI´s Scarbee Funk Guitarist
Synth: A lot of Arturia´s Synth Collections
These are my personal favourite Plugs for making Soul/RNB/Funk Style. Of course, there´s a lot of more stuff out there, a lot of other Guitar Libarys or Bass Libarys for example. But with my Plug i´m really happy for these Music Style.
Greets.