I have a Nook but I don't think it meets all of your requirements. The screen is large but I don't know about 8-10". It does not have an internal speaker, you must use headphones.
It uses 3G from ATT and will also do Wifi. If you want o save money, you can drop the 3G and get a model that only does Wifi (saves $50).
http://www.barnesandnoble.com/nook/i...?cds2Pid=30195