After much deliberation, I've decided on roughly which style I'm going to go for.  There were several other options, including a frame within a frame design, but I've settled on the relatively simple option even though it has the added expense of 3 cylinders instead of the 2 on the other ideas.  However, there is a potential problem in having a mechanical valve system that can perform all of the movements necessary.  I've emailed a load of hydraulic companies in the hope that they can offer some insight, but if anyone reading this has any ideas then please let me know!

Sorry about the lack of posts, I'm in the thick of the design stage at the moment.  As you can see from the calculations sheet, where I have the pivot point is obviously going to have a massive effect on what angle of movement I can get.  With the pivot point at the back, I can get 28.4° downwards before the nose hits the ground.  However, this is with the cockpit mounted 1m up.  With the pivot point in the centre, I can get 47.2° from 1m up.  On the other hand I could keep the 28.4°, but the cockpit would only have to be raised 50cm, making access much easier.  On the downside, this means finding a ball and socket bearing large enough to take the required loads, and working out how to attach the damn thing to the bottom of the cockpit!  Decisions, decisions!