I think its a good idea. My concerns would be covering the costs associated with operating two vehicles which will undoubtedly burn lots of petrol. The other issue is where to advertise. Pick media sources which reach your target audience but not just through internet and print. Try local events which cater to those groups also and advertise in printed handouts or cycling calendars that are printed in bike shops nearby. It may also be good to setup some sort of web based system so that potential riders can inquire about the ride, mileage, what to bring and such. Also have a back up plan in case you run into something which makes the potential route traveled impassable, like inclement weather or roadway construction. Im sure you will get other input for your idea through this source. Good thinking, it should be a good ride. Time to round up your staff and potential riders and calculate costs that need to be covered.