Ramps or davits?

dave the rave

I have a 15ft speedboat and a Ford streetka which I would like to take on my tours.One of the two could be towed,on a trailer,but the other will need to go on the roof of my motorhome (there is not room inside becasuse we will need to eat and sleep etc).I
am unable to decide if ramps or davits would be the best way forward to load onto the roof!.If I use ramps I would also need a winch mounted on the roof to load the boat (slightly lower profile than the Ka) or should I drive the Ka onto the roof and use a
proper boat trailer?Any suggestions?