I took a few tries to figure it out. I gave the gentleman at Bansbach (easylift.com) as much info as I could. Initially I was thinking to use the same mounting brackets the actuator uses, but we couldn't get that done. The hatch on the portside is odd shaped on the 278 and even the actuator hits the deck. The starboard side is squared and offers a little more room. I'll have to move the genset muffler a little, but that's four screws. The idea is to use the muffler base to mount the shock mount.
After a little shock engineering graphs showing the coordinates of how to properly mount it, we ended up with a single shock a little over 4 feet (1287 mm) extended, and 2+ feet collapsed (687 mm). Shock pressure 605 N.

(This company uses the metric system) Any shock not in stock at their Melbourne, Florida office has to be special ordered from Germany. If I gave them the proper weights it should take very little effort to open the hatch.
They can make just about anything to fit your hatch. At first they tried to use a shock that they had in shock, but the choices he gave all came up short. The nice thing is that the hatch will open to 60 degrees instead of the current 45.
All in all it has been nice and easy working with them if that's the route you decide to go.