RE: Which Kindle to Choose ? - Our 2012 Kindle Buyer's Guide
For point 1, this will be fine on any model Kindle as long as you can access your Amazon.co.uk (or .com) account via the computer.
For point 2, (3G btw) I don't really know enough to about this side of things to be able to say one way or the other. Probably the best thing to do in this instance is contact Amazon support and ask them.