well I have a few of those pumps for blowing up tubes, and I have a Air Dock inflatable boat lift that has a large air pump on it already to use. but I dont know if it will have enough PSI to push the water out, the other pumps are normally not pressure ratter, rather than how much CFM's they can put out. I am thinking the cheap 150psi tire pumps you can get for your car. I have power out there and it would be easier than running 1000ft of air hose from the garage.
Peter, I think the shackles could probably be bought from a trailer supply store, I am using SS eye bolts as of now, and they hold quite well. But I think 4 would be good and make 2 pontoons out of them and then just make sure you have enough length on the bunks to not have a steep incline, but its looks like thats all the hydro hoist system is.