I am not sure which Roland module you are looking at, though. Unfortunately, Roland don't make a module with the components that are in the G70/E80... You would need a TD drum module AND a Fantom module to get close (and a VK module for the Hammond stuff).

You MIGHT be better off using a G70, and having a Yamaha module, instead, for the SA stuff you like so much and the Mega voices... When it comes out, I am planning on seeing if the MotifXS Rack will do this for me. I'll keep you posted.