I have loaded the bike both ways you have said. The tw is not too heavy so loaded that way is not too bad. I keep the weight on the left side when riding up and sitting on the bike. You might just use a plank on the right side instead of getting another ramp. You just need something to put your foot on.
They do make a unit that you load an winch it up. I have seen it work. It is real slick and pricy. I wasn[t that interested, so I can't tell you who made it or the price. I just knew I could not aford that type of deal.