The tablet Harry mentioned seems like it will suit you're needs just fine. However just to give you more options there is also the HTC Flyer, it's a 7th inch tablet based on Android 2.2 Os and the only capacitive screen device with an integrated pen as a part of the device. It also integrates well with dropbox and evernote so you can archive all of your scribes notes on evernote.
To have text to speech for pdfs you will need to drop a whopping $1 USD and buy ezPDF. This app has TTS for PDFs and also supports PDF annotations. Though for annotating PDFs I think RepliGo is better.
The Flyer is not out yet but should be out any time now.