Hello Gary and welcome to MobileRead. You didn't indicate your location when you set up your profile and that may be pertinent in selecting a reader. I live in the USA and have both a Kindle (v1) and a Sony 505.
You'll want to spend some time reading through the information in MobileRead's Wiki (
https://wiki.mobileread.com/) since it has data on most, if not all, of the available E-Book readers.
The Kindle is only available from Amazon.com. Amazon does not sell the Kindle outside of the USA, but there are many people around the world who own Kindles -- to purchase one, you have to have a US address for shipping. I believe it's easy enough to get a Kindle through eBay or other reseller, even if you don't live in the USA.
On the other hand, Sony is selling its 505 (and maybe the 700?) in Canada, the UK, and Germany. Maybe other countries, but I haven't kept up with the announcements -- check the Wiki. In the USA, you can purchase Sony readers in some Target, Borders, and Fry Electronics stores. I've also seen them in vending machines in large airports.
Other major brands include Cybook, IRex, Hanlin (which is also sold under other brand names such as BeBook and EZ Reader), JetBook, and EBookwise. Again, check out the wiki for sources. Last week I saw the JetBook and EZ Reader (along with the Sony readers) in Fry Electronics here in Dallas, TX. JetBook is also supposed to be available in some Bed, Bath, and Beyond stores.
Regardless of which reader you choose, you're in for a treat. The convenience of carrying one small device with lots of books in it was a major selling point for me.
And, while you're waiting -- check out the free E-Books available here at MobileRead. You can get the reading software for just about any computer system -- I can recommend Calibre which runs on Windows, Mac OSX, and Linux.
Welcome to MobileRead. Good luck in choosing a reader.