Hello and welcome to Mobileread, blackcat.
I'm sorry you haven't had a response yet. I not very knowledgeable about pdf ability of the various devices.
I do know that if you are in the UK another aspect about ebook purchases is geographic restriction. You may be able to see ebooks for sale on a site, but when you get to the purchase point it will display that it is not available to your area/country, if it has geographic restriction. This is not the fault of the store fronts, but due to publishing companies not always having the right to sale ebooks in other countries.
MR (Mobileread) has many very knowledgeable members and hopefully some will chime in soon.
Have fun exploring the forums.
