Hello,
Hope you doing well.
We would like to assist you on this requirement as we are already experienced into this. We have already developed couple of websites related to this and we can make it run on Mac OSX.
I strongly feel that before we can arrive on a fair conclusion for the price and timeline, I would need more details about the Project which will help us understand your vision and place a firm bid. So please consider this as a placeholder bid.
Thank you.