The thing with tubular motors is that they need adapters to either fit and lock to the tube profile as they are inserted into the tube, and/or the drive adapters are screwed to the tube. This is why your tube inside diameter and profile are important to sizing a motor and adapter combo.
The battery motors currently work with Somfy RTS Radio and there is already a plug-in for the Univeral RTS Interface for Vera via a serial to USB cable. But keep in mind that this is a one-way communication and won't report status and confirm movement like Z-Wave.
Look at your clutch on the manual shades to see if they are Rollease or some other known company that Somfy may already have an adapter for.
The Somfy ST-30 is the most quiet option, but could be the most expensive considering Motor/Z-Wave Box/Power Supply. The ILT is the next quietest motor, but it is AC and would require a larger tube/box on the window/etc, but saves some money because you don't need the Power Supply like with the ST-30. Then there is the Somfy Standard Motor used with an ESI ABMHZ or Lagotek AC1-ZW external controller which can be ordered quiet, but you'll have to find a place for the external motor controller (homerun wires back to central area or fit the control box in the shade valance, etc).
http://www.lagotek.com/blindspdf/AC1-ZW%20Cut%20Sheet.pdf