If you can track down a Voltage Block, that will be a good addition to your modulation sources. You probably want to look for a matrix mixer, or at the very least a Happy Nerding 3xMIA, to combine/attenuate/polarize modulation sources.
Have fun and good luck!
-- farkas
Thank you so much for your thoughts. Definitely keen on a Voltage Block when I am able to find one and I will check out the 3xMIA :-)