Radar35
I can't help but think that if you are seriously looking for a flight planning system for a new business then asking this sort of question on PPrune isn't going to get you very far. Selection of a flight planning system to meet this sort of need is no easy task.
May I suggest that you develop a system specification and your budget parameters; do your research online- contact those companies who offer a system that might meet your needs and speak with them directly- ask them to come demonstrate the system to you- come up with a short list of three or so system's that could work for you. Importantly establish who their present customers are and once you've done all that- then start asking around the business for views on how well your short list of system's work and go and see them in action.
You're putting the cart before the horse by asking such a wide ranging question here.