smart move snapping at someone who just spend their own free time trying to help you. Not. My answer is the exact same. Go and ask the shop! I don't own the iTennis machines myself and didn't make the measurement for the pro one when I had it for testing.
If you just want him to answer your questions, you have the option to PM him. And for questions about specs and small details of the machine, I think the shop is the best place to ask. They are really reactive so do not hesitate. Otherwise, we would gladly answer other questions about the use of the machine, our impressions etc Have a nice day !