Marathon Pluses are heavy, it's true. They aren't the liveliest ride, and the traction, though perfectly good on paved roads, isn't as great as some on loose surfaces.

However, they are remarkably durable and their resistance to punctures is exemplary. They last and last, and I have done over 7000 miles with just one flat.

If you go for these tyres, I'd say the choice of tube is immaterial. Some of the lighter tyres, with very supple sidewalls, might benefit from your choosing a heavier tube.

One other thought. The Marathon XR, now discontinued, was a superb touring tyre - rode better than the Plus, and was very robust, if not quite as bombproof. Schwalbe have now replaced it with the Marathon Mondial. I haven't had a chance to try one yet (the Marathon Pluses won't wear out!) but they may be worth looking at.