For use with the Roland Fantom-G Series Workstation keyboards, the ARX-01 Drums Expansion Board could be a music-production dream. Being that it is a synth intself and that it has Roland's proprietary SuperNATURAL sound technology, the expansion board promises complete control of the elements of each drum, such as shell depth and muffling. Once each drum is crafted the way you want, you can further refine it with the built-in compressor/EQ, reverb, powerful multieffects, and an onboard mixer for adjusting the volume and pan position.
If this sounds like the ticket for you, check out the Roland website. US list price: $449.00.