Hi Dave
I will second the recommendation for Matthew Reilly. As mentioned, his writing is a bit ordinary at times but his plotting and pacing is very good. He has a very visual way of writing, like an action movie in print. At the moment he is the only action/thriller writer that I read - I only picked up Ice Station because it was set in Antarctica. I would recommend starting with Ice Station, his second novel. His first, Contest, is a stand-alone and quite honestly not as good. I'm afraid I don't know if they are available as ebooks - mine are pbooks.
You might also like to check out Gnooks, which helps you find similar writers. There are other similar sites, but I can't recall their names right now.
http://www.gnooks.com/
Enjoy!