When it comes to vocal sounds, I would recommend using some sampler. When it comes to the instruments, this is where Roland should continue to support the SRJV line, especially since SRJV slots are available in the new XV synths.

Now the SRJV19 Guitar & Drums and SRJV20 Sample ROM expansion board should become a reality. We've already seen that 16MB ROM can yeild some very high quality waveforms with the SRJV10 Bass & Drums. Now, we should do that for Guitar.

My Current Exp. Board Setup:

Hip-Hop, Bass&Drums, Exp I, ExpII

My Future Exp. Board Setup

Hip-Hop, Bass & Drums, Session, Piano [or] Hip-Hop, Bass & Drums, Session, Guitar