Scott, mine does not have a standing platform. I have talked with Bill and he is working on a sliding platform for the Osprey. I would want the leaning bar as well if I was standing.
I transport my cat on top of my Suburban. I have the aluminum wheel attached to the back of the frame so I just wheel it up to the truck and push it up onto the roof rack. I use four tie down straps and have hauled it all over the northwest at over freeway speeds. With the anchor attachments, rod holders etc. I would guess mine weighs 80 pounds.
As it relates to motor mounts and what to use for power, contact Bill Day directly through the web site and I am sure that he will help.
Let me know if you have any other questions.
Best regards, Steve