I would say get a 6x8 to start with as it's very easy to travel with (also around the home). I really like the Intuos 3 by Wacom (see my sig) as I think having a nice feeling grip pen makes a vast difference than the all plastic pens (just my feeling). I think once you use it for about a week it will become second nature. I use it to browse the web and well, everything but typing.
I would go to an Apple Store or any local shop that has them on display at test one out. I know you are thinking about $$$ but a tablet is a very good investment and if you only do it once, spend a bit more and get one that feels the best in your hand (it will thank you later 😉).
I would go wired over any BT/wireless tablet but again it's just my take on it. Good luck and enjoy the one you choose 🙂