Hi Mark and all!
Nice project!! I think you sould define the objectives more clearly.
So, do you want total energy yield? Then no need for double orientation, just pointing south (if you are in the north hemisfere, and around 30 degrees tilted. Typical and easy.
Do you want a nice steady output along the day? Then because of panels getting 15% cheaper each year, or more, the thing could just be to have twice as many panels and have half looking to the morning sun and half at the evening sun. Tracking could still make sense I guess.
That said, I must admit I am a solar tracker fan. And in my professional time in Spain working with PV I designed many trackers on paper. Many is around 50!!!
One of the main criteria when you do a tracker is wind resistance. More about that later.
And I guess you are aiming at simplicity here.
So my recomendation is a one axis tracker but with a polar axis.
Made by a large company with a cheap and very deployable. It is my favourite.
Check of course the wikipedia article on: http://en.wikipedia.org/wiki/Solar_tracker
Then for the movement I would do a mechanical system that does not get broken with wind blows. A good option there is to move the panels by the motor relocating a hanging weight, and then a damper.
My last year engineering project, in spanish, has a comparison on solar tracker models. More on that later.
I live in Berlin, met Pavlik recently here. Dont know exactly how we could collaborate. Bye!!