Good news, after researching various online eBook services, I settled on Smashwords. Book three, Red Star Conspiracy, is now available in a variety of DRM free formats at:
http://www.smashwords.com/books/view/10440
You can sample 30% of the book before deciding whether to purchase. They feed a variety of other online eBook retailers, so their service appeared to provide the best exposure.
Enjoy!