I just picked up an air lift. Decent quality, even if it is Chinese made. A higher lift capacity than you were looking at (1500 lb). Mine came with a center jack and comes with front extension so it can handle any length bike. I have not had the Rocket on it yet, I have an old Bonnyville on it for the winter. Getting to old to be lying on cold concrete. I bought the side extensions for mine but have taken them off as my garage gets a bit crowded. I think the side extensions would be ideal for loading the Rocket into a truck as you can sit on the bike and have your feet reach the platform. No worries about stability or lift capacity. The air cylinder is huge.
I am happy with mine and I paid considerably more than what you can buy them for in the US. I get the feeling that this is going to be one of those shop tools I wonder how I ever got by without.