The current show at the Reykjavik Museum of Photography is done by a large format photographer. Her name is Jessica Auer, and splits her time between Canada and Iceland. I think the majority of the work, if not all, was done on a Chamonix 4x5.

As for advice, I would agree with Guðmundur. Beautiful landscapes are not that hard to find, but you are coming at the most crowded time, so you will probably want to avoid the largest tourist spots, at least for your photography. It is still worth seeing a lot of them. I don't think you will need to deal with such extreme conditions, as you will be coming in July. It may be windy and rainy though.

Other general advice: don't ever turn your back on the waves at Reynisfjara...several people have died in the past few years, including one this year. The waves are not consistent...everything is fine until all of a sudden a much larger wave comes and sweeps people off their feet into the sea, even good swimmers.

It is hard to find or buy any large format photography materials here, so make sure you come with everything you need.